Application of in vitro Myo-differentiation of non-muscle cells to enhance gene expression and facilitate analysis of muscle proteins.

Introduction of the myogenic-determination gene MyoD forces non-muscle cell cultures into myogenesis, thereby inducing expression of muscle-specific proteins and facilitating their analysis. In several MyoD-transfected fibroblasts, immunohistochemical detection showed expression of desmin after three days, of titin after five days and of dystrophin after seven days. Cell fusion (myotube formation) could be observed after five days. After nine days a fraction of the cells showed a striated titin pattern, indicating an advanced state of muscle differentiation. Dystrophin (the protein absent in Duchenne Muscular Dystrophy patients) can be detected in MyoD-transfected and differentiated fibroblasts from healthy individuals, and is absent in those of patients. MyoD-transfection increases transcription of the dystrophin gene, facilitating RNA-based mutation detection. Using RNA from MyoD-transfected, differentiated fibroblasts of a deceased patient with an unknown, non-deletion mutation, we were able to identify a CGA-->TGA nonsense mutation in the rod domain at basepair 6492 and to establish a rapid mutation specific test for future diagnosis of the mutation in his relatives.

Introduction of the

    myogenic-determination gene MyoD forces non-muscle cell cultures into myogenesis
    GENETICS

, thereby inducing expression of muscle-specific proteins and facilitating their analysis. In several

    MyoD-transfected fibroblasts
    MICROSCOPIC

,

    immunohistochemical detection
    PARACLINICAL

 showed

    expression of desmin
    BIOCHEMICAL

 after three days,

    of titin
    BIOCHEMICAL

 after five days and of dystrophin after seven days.

    Cell fusion (myotube formation)
    MICROSCOPIC

 could be observed after five days. After nine days a

    fraction of the cells showed a striated titin pattern
    MICROSCOPIC

, indicating an

    advanced state of muscle differentiation
    MICROSCOPIC

. Dystrophin (the protein absent in

    Duchenne Muscular Dystrophy
    DIAGNOSIS

 patients) can be detected in

    MyoD-transfected and differentiated fibroblasts
    MICROSCOPIC

 from healthy individuals, and is absent in those of patients.

    MyoD-transfection
    MEDICATION

    increases transcription of the dystrophin gene
    GENETICS

, facilitating

    RNA-based mutation detection
    PARACLINICAL

. Using

    RNA from MyoD-transfected, differentiated fibroblasts
    PARACLINICAL

 of a deceased patient with an

    unknown, non-deletion mutation
    GENETICS

, we were able to identify a

    CGA-->TGA nonsense mutation in the rod domain at basepair 6492
    GENETICS

 and to establish a rapid mutation specific test for future diagnosis

    of the mutation in his relatives
    FAMILY

.


Acute gastric dilatation in Duchenne muscular dystrophy: a case report and review of the literature.

Duchenne muscular dystrophy (DMD) is the most common neuromuscular disorder of childhood. Its clinical characteristics that derive from skeletal muscle involvement have been well described. Less well known is that visceral smooth muscle is affected in DMD. We report a case of a 19-year-old man with DMD who presented with severe nonradiating epigastric pain. He was initially sent home from the emergency department with a diagnosis of costochondritis. Acute gastric dilation was not considered in the differential diagnosis despite supportive history, physical examination findings, and radiographs. The case illustrates the lack of familiarity by clinicians of the gastrointestinal manifestations of DMD, including gastric dilatation and intestinal pseudoobstruction. Following a case discussion, the literature relevant to acute gastric atony is reviewed.

    Duchenne muscular dystrophy (DMD)
    DIAGNOSIS

 is the most common

    neuromuscular disorder
    DIAGNOSIS

 of

    childhood
    AGE

. Its clinical characteristics that derive from

    skeletal muscle involvement
    SYMPTOMS

 have been well described. Less well known is that

    visceral smooth muscle
    SYMPTOMS

 is affected in

    DMD
    DIAGNOSIS

. We report a case of a

    19-year-old
    AGE

    man
    GENDER

 with

    DMD
    DIAGNOSIS

 who presented with

    severe nonradiating epigastric pain
    SYMPTOMS

.

    He
    GENDER

 was initially sent home from the emergency department with a diagnosis of

    costochondritis
    DIAGNOSIS

.

    Acute gastric dilation
    SYMPTOMS

    was not considered in the differential diagnosis
    NEG_FINDINGS

 despite supportive history, physical examination findings, and

    radiographs
    PARACLINICAL

. The case illustrates the lack of familiarity by clinicians of the

    gastrointestinal manifestations
    SYMPTOMS

 of

    DMD
    DIAGNOSIS

, including

    gastric dilatation
    SYMPTOMS

 and

    intestinal pseudoobstruction
    SYMPTOMS

. Following a case discussion, the literature relevant to

    acute gastric atony
    SYMPTOMS

 is reviewed.

Duchenne muscular dystrophy (DMD)
neuromuscular disorder
DMD
DMD
costochondritis
DMD

skeletal muscle involvement
visceral smooth muscle
severe nonradiating epigastric pain
Acute gastric dilation
gastrointestinal manifestations
gastric dilatation
intestinal pseudoobstruction
acute gastric atony


[The effect of clomipramine to nocturnal periodic hypoxemia in Duchenne muscular dystrophy].

Respiratory insufficiency is a major cause of death in Duchenne muscular dystrophy (DMD). The earliest sign is a hypoventilation which appears in REM sleep. We administered 20 mg of clomipramine hydrochloride before sleep to two DMD patients with periodic nocturnal hypoxemia. The complaints such as morning headache, nausea and somnolence disappeared promptly. Polysomnography revealed complete suppression of REM sleep and disappearance of periodic hypoxemia in both cases. The most important untoward effect was intractable constipation observed in one patient. Although clomipramine dramatically improved the nocturnal periodic hypoventilation, the therapeutic effects lasted less than three months. Permanent REM sleep suppression is requisite for optimal drug therapy of periodic nocturnal hypoventilation in DMD.

    Respiratory insufficiency
    SYMPTOMS

 is a major cause of

    death
    SYMPTOMS

 in

    Duchenne muscular dystrophy (DMD)
    DIAGNOSIS

. The earliest sign is a

    hypoventilation
    SYMPTOMS

 which appears in REM sleep. We

    administered 20 mg of clomipramine hydrochloride before sleep
    MEDICATION

 to two

    DMD
    DIAGNOSIS

 patients with

    periodic nocturnal hypoxemia
    SYMPTOMS

. The complaints such as

    morning headache
    SYMPTOMS

,

    nausea
    SYMPTOMS

 and

    somnolence
    SYMPTOMS

 disappeared promptly.

    Polysomnography
    PARACLINICAL

 revealed

    complete suppression of REM sleep
    SYMPTOMS

 and

    disappearance of periodic hypoxemia
    SYMPTOMS

 in both cases. The most important untoward effect was

    intractable constipation
    SYMPTOMS

 observed in one patient. Although

    clomipramine
    MEDICATION

    dramatically improved the nocturnal periodic hypoventilation
    SYMPTOMS

, the

    therapeutic effects lasted less than three months
    NEG_FINDINGS

.

    Permanent REM sleep suppression
    MEDICATION

 is requisite for optimal drug therapy of

    periodic nocturnal hypoventilation
    SYMPTOMS

 in

    DMD
    DIAGNOSIS

.

Duchenne muscular dystrophy (DMD)
DMD
DMD


Quantitative and qualitative alterations of dystrophin are expressed in muscle cell cultures of Xp21 muscular dystrophy patients (Duchenne and Becker type).

The authors studied skeletal muscle cell cultures from four control subjects, two patients with Duchenne muscular dystrophy, two Duchenne carriers and three patients with Becker muscular dystrophy with different phenotypes. Western blotting was performed on well-differentiated myotubes and compared with the results obtained in muscle tissue. In all cultures the band of dystrophin closely corresponded to the one observed in muscle tissue: both quantitative and qualitative defects were observed. This confirms the early expression of the Xp21 gene defect in uninnervated muscle cultures and supports the usefulness of muscle cultures both in diagnostic procedure and as a model to study the disease.

The authors studied

    skeletal muscle cell cultures
    MICROSCOPIC

 from four control subjects, two patients with

    Duchenne muscular dystrophy
    DIAGNOSIS

, two

    Duchenne
    DIAGNOSIS

 carriers and three patients with

    Becker muscular dystrophy
    DIAGNOSIS

 with different phenotypes.

    Western blotting
    PARACLINICAL

 was performed on

    well-differentiated myotubes
    MICROSCOPIC

 and compared with the results obtained in

    muscle tissue
    PARACLINICAL

. In all cultures the

    band of dystrophin closely corresponded to the one observed in muscle tissue
    SYMPTOMS

:

    both quantitative and qualitative defects
    SYMPTOMS

 were observed. This confirms the

    early expression of the Xp21 gene defect
    GENETICS

 in

    uninnervated muscle cultures
    MICROSCOPIC

 and supports the usefulness of

    muscle cultures
    MICROSCOPIC

 both in diagnostic procedure and as a model to study the disease.

Duchenne muscular dystrophy
Duchenne
Becker muscular dystrophy


Nursing practice management: muscular dystrophy.

The Nursing Practice Management section displays a health care plan for a student with Duchenne Muscular Dystrophy. Following a brief overview of the pathophysiology of the disorder, a case study is presented from which a nursing process-based plan of care is derived.

The Nursing Practice Management section displays a

    health care plan
    MEDICATION

 for a student with

    Duchenne Muscular Dystrophy
    DIAGNOSIS

. Following a brief overview of the pathophysiology of the disorder, a case study is presented from which a

    nursing process-based plan of care
    MEDICATION

 is derived.

health care plan
nursing process-based plan of care


DMD and BMD in the same family due to distinct mutations.

We report on a family with a boy affected by Duchenne muscular dystrophy (DMD) and an asymptomatic cousin with a Becker-type dystrophin abnormality, diagnosed by chance. Dystrophin gene analysis showed that these conditions were caused by two distinct deletions with breakpoints in different exons. In Xp21 families, DNA analysis and dystrophin testing of asymptomatic males with high CK plasma levels might detect different dystrophin mutations in separate haplotypes as in our family, although we stress there should be clear clinical or familial indications for such testing.

We report on a

    family with a boy
    FAMILY

    affected by Duchenne muscular dystrophy (DMD)
    FAMILY

    and an asymptomatic cousin with a Becker-type dystrophin abnormality
    FAMILY

, diagnosed by chance.

    Dystrophin gene analysis
    PARACLINICAL

 showed that these conditions were caused by

    two distinct deletions with breakpoints in different exons
    GENETICS

. In

    Xp21
    GENETICS

 families,

    DNA analysis
    PARACLINICAL

 and

    dystrophin testing
    PARACLINICAL

 of

    asymptomatic
    NEG_FINDINGS

    males
    GENDER

 with

    high CK plasma levels
    BIOCHEMICAL

 might detect

    different dystrophin mutations in separate haplotypes
    GENETICS

 as in our family, although we stress there should be clear clinical or familial indications for such testing.


Duchenne muscular dystrophy and idiopathic hyperCKemia segregating in a family.

A 7-month-old boy with gross motor delay and failure to thrive presented with rhabdomyolysis following an acute asthmatic episode. During hospitalization an electrocardiographic conversion to a Wolff-Parkinson-White type 1 (WPW) pattern took place. Duchenne muscular dystrophy (DMD) was suspected based on elevated creatine kinase (CK) serum levels, muscle biopsy, and family history. The diagnosis was confirmed by molecular analysis, which documented a deletion corresponding to cDNA probe 1-2a in the dystrophin gene, in the propositus and in an affected male cousin of his mother. "Idiopathic" hyperCKemia was found in the propositus, his father, and 5 of his relatives. We suggest that the unusually early and severe manifestations of DMD in this patient may be related to the coincidental inheritance of the maternal DMD gene and of a paternal gene, causing hyperCKemia.

A

    7-month-old
    AGE

    boy
    GENDER

 with

    gross motor delay
    SYMPTOMS

 and

    failure to thrive
    SYMPTOMS

 presented with

    rhabdomyolysis
    SYMPTOMS

 following an

    acute asthmatic episode
    SYMPTOMS

. During hospitalization an

    electrocardiographic conversion to a Wolff-Parkinson-White type 1 (WPW) pattern
    SYMPTOMS

 took place.

    Duchenne muscular dystrophy (DMD)
    DIAGNOSIS

 was suspected based on

    elevated creatine kinase (CK) serum levels
    BIOCHEMICAL

,

    muscle biopsy
    PARACLINICAL

, and

    family history
    PARACLINICAL

. The diagnosis was confirmed by

    molecular analysis
    PARACLINICAL

, which documented a

    deletion corresponding to cDNA probe 1-2a in the dystrophin gene, in the propositus and in an affected male cousin of his mother
    GENETICS

. "

    Idiopathic" hyperCKemia
    BIOCHEMICAL

    was found in the propositus, his father, and 5 of his relatives
    FAMILY

. We suggest that the

    unusually early and severe manifestations of DMD
    SYMPTOMS

 in this patient may be related to the

    coincidental inheritance of the maternal DMD gene and of a paternal gene
    GENETICS

, causing

    hyperCKemia
    BIOCHEMICAL

.


Deficiency of brain synaptic dystrophin in human Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is characterized by a defect in dystrophin, a high molecular weight protein that is located predominantly in muscle, but which has been detected in brain. Brain dystrophin has been localized to the synapse, in the postsynaptic density (PSD), and is absent in the mdx mouse, an animal model of human DMD. To define the potential pathogenic role of dystrophin deficiency in cognitive impairment, we examined the protein in human DMD brain. The 427-kd dystrophin was absent in the PSD from DMD brain, but was normally expressed in the brain from an age-matched control subject. Our findings indicate that dystrophin is deficient in human DMD cortical synapses and provide a potential pathogenic mechanism for cognitive impairment.

    Duchenne muscular dystrophy (DMD)
    DIAGNOSIS

 is characterized by a

    defect in dystrophin
    GENETICS

, a high molecular weight protein that is located predominantly in muscle, but which has been detected in brain. Brain dystrophin has been

    localized to the synapse, in the postsynaptic density (PSD)
    MICROSCOPIC

, and is absent in the

    mdx
    DIAGNOSIS

 mouse, an animal model of human

    DMD
    DIAGNOSIS

. To define the potential pathogenic role of

    dystrophin deficiency
    BIOCHEMICAL

 in

    cognitive impairment
    SYMPTOMS

, we examined the protein in human

    DMD
    DIAGNOSIS

 brain. The

    427-kd dystrophin was absent in the PSD from DMD brain
    GENETICS

, but was normally expressed in the brain from an age-matched control subject. Our findings indicate that dystrophin is

    deficient in human DMD cortical synapses
    MICROSCOPIC

 and provide a potential pathogenic mechanism for

    cognitive impairment
    SYMPTOMS

.

Duchenne muscular dystrophy (DMD)
mdx
DMD
DMD

cognitive impairment
cognitive impairment


Adhalin gene mutations in patients with autosomal recessive childhood onset muscular dystrophy with adhalin deficiency.

Homozygous adhalin gene mutations were found in three patients from two consanguineous families with autosomal recessive childhood onset muscular dystrophy. Muscle biopsies from patients in each family showed complete absence of adhalin. Sequencing of adhalin cDNA prepared from skeletal muscle by reverse transcription PCR demonstrated a cytosine to thymidine substitution at nt 229 in the patient in family 1 and an adenine to guanine substitution at nt 410 and a 15-base insertion between nt 408 and 409 in the two patients in family 2. Sequencing of genomic DNA prepared from peripheral blood leukocytes by PCR confirmed these mutations. The parents in each family were found to be heterozygous for the respective mutations. These adhalin gene mutations are presumed to be responsible for the absence of adhalin in the skeletal muscle. Adhalin deficiency likely causes disruption of the muscle cell membrane, resulting in dystrophic changes in the skeletal muscle similar to dystrophin deficiency in Duchenne muscular dystrophy.

    Homozygous adhalin gene mutations
    GENETICS

 were found in three patients from two

    consanguineous families
    FAMILY

 with

    autosomal recessive childhood onset muscular dystrophy
    DIAGNOSIS

.

    Muscle biopsies
    PARACLINICAL

 from patients in each family showed

    complete absence of adhalin
    BIOCHEMICAL

.

    Sequencing of adhalin cDNA prepared from skeletal muscle by reverse transcription PCR
    PARACLINICAL

 demonstrated a

    cytosine to thymidine substitution at nt 229
    GENETICS

 in the patient in family 1 and

    an adenine to guanine substitution at nt 410 and a 15-base insertion between nt 408 and 409
    GENETICS

 in the two patients in

    family 2
    FAMILY

.

    Sequencing of genomic DNA prepared from peripheral blood leukocytes by PCR
    PARACLINICAL

 confirmed these mutations.

    The parents in each family were found to be heterozygous for the respective mutations
    FAMILY

. These

    adhalin gene mutations
    GENETICS

 are presumed to be responsible for the

    absence of adhalin in the skeletal muscle
    BIOCHEMICAL

.

    Adhalin deficiency
    BIOCHEMICAL

 likely causes

    disruption of the muscle cell membrane
    MICROSCOPIC

, resulting in

    dystrophic changes in the skeletal muscle
    SYMPTOMS

 similar to

    dystrophin deficiency
    SYMPTOMS

 in

    Duchenne muscular dystrophy
    DIAGNOSIS

.


A severe muscular dystrophy patient with an internally deleted very short (110 kD) dystrophin: presence of the binding site for dystrophin-associated glycoprotein (DAG) may not be enough for physiological function of dystrophin.

We report a 4-yr and 5-month-old boy with severe clinical features of an early-onset Duchenne muscular dystrophy, who had a very short (110 kDa) dystrophin at the sarcolemma. The patient had a large deletion (exons 2-44) of the dystrophin gene which was predicted to cause a reading frame shift. Sequence analysis of dystrophin mRNA in muscle revealed an alternatively spliced gene product from exons 1 to 51 that caused restoration of the reading frame, in addition to an mRNA corresponding to the DNA deletion. A consistent result was obtained by immunocytochemical analysis of muscle; i.e. positive staining for dystrophin at the sarcolemma using antibodies against the C-terminus, cysteine-rich region and last three of 24 repeat units of the central rod-domain, but not for the remaining antibodies for dystrophin that recognize the N-terminal and proximal rod-domains. Immunostaining for dystrophin-associated glycoproteins (DAGs: 43 and 50 K) and merosin were preserved. Utrophin staining was positive but fainter than other DMD muscles. These results suggest that an extremely short dystrophin lacking the entire actin-binding site in the N-terminus cannot function properly even if the protein possesses the putative DAG-binding cysteine-rich and the C-terminal domains, and still has an ability to associate with sarcolemmal membrane.

We report a

    4-yr and 5-month-old
    AGE

    boy
    GENDER

 with

    severe clinical features
    SYMPTOMS

 of an

    early-onset Duchenne muscular dystrophy
    DIAGNOSIS

, who had a

    very short (110 kDa) dystrophin at the sarcolemma
    MICROSCOPIC

. The patient had a

    large deletion (exons 2-44) of the dystrophin gene which was predicted to cause a reading frame shift
    GENETICS

.

    Sequence analysis of dystrophin mRNA in muscle
    PARACLINICAL

 revealed an

    alternatively spliced gene product from exons 1 to 51 that caused restoration of the reading frame
    GENETICS

, in addition to an

    mRNA corresponding to the DNA deletion
    GENETICS

. A consistent result was obtained by

    immunocytochemical analysis of muscle
    PARACLINICAL

; i.e.

    positive staining for dystrophin at the sarcolemma
    MICROSCOPIC

 using

    antibodies against the C-terminus, cysteine-rich region and last three of 24 repeat units of the central rod-domain
    BIOCHEMICAL

, but

    not for the remaining antibodies for dystrophin that recognize the N-terminal and proximal rod-domains
    NEG_FINDINGS

.

    Immunostaining for dystrophin-associated glycoproteins (DAGs: 43 and 50 K) and merosin
    BIOCHEMICAL

    were preserved
    NEG_FINDINGS

.

    Utrophin staining was positive but fainter than other DMD muscles
    BIOCHEMICAL

. These results suggest that an

    extremely short dystrophin lacking the entire actin-binding site in the N-
    GENETICS

terminus cannot function properly even if the protein possesses the

    putative DAG-binding cysteine-rich and the
    GENETICS

 C-terminal domains, and still has an ability to associate with sarcolemmal membrane.


Tracheal occlusion in the prone position in an intubated patient with Duchenne muscular dystrophy.

A 15-year-old boy with Duchenne muscular dystrophy developed complete airway obstruction under general anaesthesia when positioned prone for spinal surgery. Tracheobronchial compression against vertebral bodies facilitated by a shortened sternovertebral distance due to thoracic lordoscoliosis is suggested as the cause.

A

    15-year-old
    AGE

    boy
    GENDER

 with

    Duchenne muscular dystrophy
    DIAGNOSIS

 developed

    complete airway obstruction
    SYMPTOMS

 under

    general anaesthesia
    MEDICATION

 when

    positioned prone for spinal surgery
    MEDICATION

.

    Tracheobronchial compression against vertebral bodies
    SYMPTOMS

 facilitated by a

    shortened sternovertebral distance
    SYMPTOMS

 due to

    thoracic lordoscoliosis
    SYMPTOMS

 is suggested as the cause.

general anaesthesia
positioned prone for spinal surgery


X-chromosome methylation in manifesting and healthy carriers of dystrophinopathies: concordance of activation ratios among first degree female relatives and skewed inactivation as cause of the affected phenotypes.

The X-chromosome activity states of 11 manifesting carriers of dystrophinopathies, all with normal karyotypes, were estimated by restriction fragment length polymorphism (RFLP)-methylation analysis with the probes M27 beta (DXS255), p2-19(DXS605) and pSPT/PGK (PGK1) to test the role of skewed X-inactivation ratios as the cause of their affected phenotypes. In eight cases preferential inactivation of the putative X chromosome carrying the normal dystrophin allele in > or = 90% of their peripheral lymphocytes was observed, two cases showed non-apparent deviant ratios (60:40 and 70:30) from the theoretically expected values around the mean of 50% and in one case the three markers employed yielded no information. The analysis of the X-inactivation ratio in six mother-daughter pairs, all non-manifesting Duchenne muscular dystrophy (DMD) carriers, and in the close female relatives of the patients showed: (a) neither of the two X chromosomes was preferentially inactivated with respect to their parental origin; (b) a high concordance among the activation ratios of mothers and daughters, a result difficult to explain just in terms of random X-chromosome inactivation.

The

    X-chromosome activity states
    GENETICS

 of 11 manifesting carriers of

    dystrophinopathies
    DIAGNOSIS

, all with

    normal karyotypes
    NEG_FINDINGS

, were estimated by

    restriction fragment length polymorphism (RFLP)-methylation analysis with the probes M27 beta (DXS255), p2-19(DXS605) and pSPT/PGK (PGK1)
    PARACLINICAL

 to test the role of

    skewed X-inactivation ratios
    GENETICS

 as the cause of their affected phenotypes. In eight cases

    preferential inactivation of the putative X chromosome carrying the normal dystrophin allele in > or = 90% of their peripheral lymphocytes
    GENETICS

 was observed, two cases showed

    non-apparent deviant ratios (60:40 and 70:30)
    SYMPTOMS

 from the theoretically expected values around the mean of 50% and in one case

    the three markers employed yielded no information
    NEG_FINDINGS

. The

    analysis of the X-inactivation ratio
    PARACLINICAL

 in six

    mother-daughter pairs
    FAMILY

, all

    non-manifesting
    NEG_FINDINGS

    Duchenne muscular dystrophy (DMD) carriers
    DIAGNOSIS

, and in the close

    female
    GENDER

 relatives of the patients showed: (a)

    neither of the two X chromosomes was preferentially inactivated with respect to their parental origin
    GENETICS

; (b) a

    high concordance among the activation ratios of mothers and daughters
    FAMILY

, a result difficult to explain just in terms of

    random X-chromosome inactivation
    GENETICS

.


Carrier detection of Duchenne muscular dystrophy through analysis of DNA from deciduous teeth of a dead affected child.

The sister of a child affected by Duchenne muscular dystrophy (DMD) was referred for genetic counselling to assess the risk of her being a carrier. Her brother had died 15 years previously at the age of 8. There were no other affected males in the family. There were no methods for DNA investigation at the time of the child's death and the family had never been studied for linkage with polymorphic probes on the chromosomal region Xp21. The only tissue from which an assessment of the risk could be made by DNA linkage analysis was two of the child's deciduous teeth that the parents had kept. DNA was extracted using a protocol described for the recovery of ancient DNA from museum specimens and archaeological finds. Multiplex amplification did not reveal deletions in 19 exons spanning the hot-spot regions for deletions within the dystrophin gene in Xp21. Linkage analysis using three highly polymorphic microsatellites demonstrated that the sister had not received the X chromosome borne by her brother. These results show that DNA extracted from teeth is a reliable source for molecular diagnosis.

The

    sister of a child affected by Duchenne muscular dystrophy (DMD)
    FAMILY

 was referred for

    genetic counselling
    MEDICATION

 to assess the risk of

    her
    GENDER

 being a carrier.

    Her
    GENDER

    brother had died 15 years previously at the age of 8
    FAMILY

. There were

    no other affected males in the family
    FAMILY

. There were

    no methods for DNA investigation
    NEG_FINDINGS

 at the time of the child's

    death
    SYMPTOMS

 and the

    family had never been studied for linkage with polymorphic probes on the chromosomal region Xp21
    NEG_FINDINGS

. The only tissue from which an assessment of the risk could be made by

    DNA linkage analysis
    PARACLINICAL

 was

    two of the child's deciduous teeth that the parents had kept
    MICROSCOPIC

.

    DNA was extracted
    PARACLINICAL

 using a protocol described for the

    recovery of ancient DNA from museum specimens and archaeological finds
    PARACLINICAL

.

    Multiplex amplification
    PARACLINICAL

    did not reveal deletions in 19 exons spanning the hot-spot regions for deletions within the dystrophin gene in Xp21
    NEG_FINDINGS

.

    Linkage analysis using three highly polymorphic microsatellites
    PARACLINICAL

 demonstrated

    that the sister had not received the X chromosome borne by her brother
    FAMILY

. These results show that

    DNA extracted from teeth
    PARACLINICAL

 is a reliable source for

    molecular diagnosis
    PARACLINICAL

.


Muscular dystrophy misdiagnosed as hepatic disease in a child with coeliac disease.

A 13-month-old boy presented with elevated serum aminotransferases and a flat small bowel mucosa indicating coeliac disease. He improved clinically on a gluten-free diet but serum aminotransferases continued to increase. This was found to be caused by an occult Duchenne muscular dystrophy. The case illustrates the fact that the finding of elevated serum aminotransferases in a coeliac child on a gluten-free diet should indicate that further investigations are needed to exclude coexisting disease.

A

    13-month-old
    AGE

    boy
    GENDER

 presented with

    elevated serum aminotransferases
    BIOCHEMICAL

 and a

    flat small bowel mucosa
    SYMPTOMS

 indicating

    coeliac disease
    DIAGNOSIS

.

    He
    GENDER

 improved clinically on a

    gluten-free diet
    MEDICATION

 but

    serum aminotransferases continued to increase
    BIOCHEMICAL

. This was found to be caused by an

    occult Duchenne muscular dystrophy
    DIAGNOSIS

. The case illustrates the fact that the finding of

    elevated serum aminotransferases
    BIOCHEMICAL

 in a

    coeliac
    DIAGNOSIS

    child
    AGE

 on a

    gluten-free diet
    MEDICATION

 should indicate that further investigations are needed to exclude coexisting disease.

coeliac disease
occult Duchenne muscular dystrophy
coeliac


An X:autosome translocation stabilizes truncated dystrophin: implications for lack of truncated dystrophins in Duchenne muscular dystrophy.

We report a 5-year-old girl with clinical symptoms of typical Duchenne muscular dystrophy in males. The girl showed dramatic elevations of serum creatine kinase, and muscle biopsy histopathology consistent with a severe dystrophic myopathy. Cytogenetic analysis revealed an X:22 translocation (46,X,t [X;22] [p21.2;11.2]). Dystrophin immunofluoresence studies showed strong membrane immunostaining of dystrophin with antibodies directed against the amino terminus of the protein, but vastly reduced immunostaining with carboxyl-terminal antibodies. Immunoblot studies showed a major immunoreactive protein of approximately 350 kDa at approximately 20% levels. Nested RT-PCR analysis of the dystrophin mRNA in the patient's muscle showed the RNA to be positive for primers covering the first 85% of the dystrophin coding sequence, and negative for the carboxyl-terminal 15%. Taken together, our data suggests that the translocation breakpoint occurs towards the 3' end of the gene. The translocated dystrophin gene is still expressed into a truncated dystrophin protein associated with the plasma membrane. Our results are consistent with the translocation resulting in a more stable abnormal dystrophin mRNA.

We report a

    5-year-old
    AGE

    girl
    GENDER

 with

    clinical symptoms of typical Duchenne muscular dystrophy
    SYMPTOMS

 in

    males
    GENDER

. The

    girl
    GENDER

 showed

    dramatic elevations of serum creatine kinase
    BIOCHEMICAL

, and

    muscle biopsy
    PARACLINICAL

 histopathology consistent with a

    severe dystrophic myopathy
    DIAGNOSIS

.

    Cytogenetic analysis
    PARACLINICAL

 revealed an

    X:22 translocation (46,X,t [X;22] [p21.2;11.2])
    GENETICS

.

    Dystrophin immunofluoresence studies
    PARACLINICAL

 showed

    strong membrane immunostaining of dystrophin with antibodies directed against the amino terminus of the protein
    BIOCHEMICAL

, but

    vastly reduced immunostaining with carboxyl-terminal antibodies
    BIOCHEMICAL

.

    Immunoblot studies
    PARACLINICAL

 showed a

    major immunoreactive protein of approximately 350 kDa at approximately 20% levels
    BIOCHEMICAL

.

    Nested RT-PCR analysis of the dystrophin mRNA in the patient's muscle
    PARACLINICAL

 showed the

    RNA to be positive for primers covering the first 85% of the dystrophin coding sequence, and negative for the carboxyl-terminal 15%
    GENETICS

. Taken together, our data suggests that the

    translocation breakpoint occurs towards the 3' end of the gene
    GENETICS

. The

    translocated dystrophin gene is still expressed into a truncated dystrophin protein associated with the plasma membrane
    GENETICS

. Our results are consistent with the translocation resulting in a

    more stable abnormal dystrophin mRNA
    GENETICS

.


Dysmorphic features in patients with complex glycerol kinase deficiency.

Complex glycerol kinase deficiency is a contiguous gene syndrome consisting of a deletion of the glycerol kinase locus, together with the genes for adrenal hypoplasia congenita or Duchenne muscular dystrophy or both. We describe an infant with complex glycerol kinase deficiency and mildly dysmorphic features similar to those seen in other patients, including an "hourglass" appearance of the middle of the face; hypertelorism; rounded palpebral fissures; esotropia; wide, flattened earlobes; and a downturned mouth. The combination of medical history and characteristic facies should prompt the request for specific laboratory tests diagnostic for this potentially treatable condition.

    Complex glycerol kinase deficiency
    DIAGNOSIS

 is a

    contiguous gene syndrome
    GENETICS

 consisting of a

    deletion of the glycerol kinase locus, together with the genes for adrenal hypoplasia congenita
    GENETICS

 or

    Duchenne muscular dystrophy
    DIAGNOSIS

 or both. We describe an

    infant
    AGE

 with

    complex glycerol kinase deficiency
    BIOCHEMICAL

 and

    mildly dysmorphic features similar to those seen in
    SYMPTOMS

 other patients, including

    an "hourglass" appearance of the middle of the face
    SYMPTOMS

;

    hypertelorism
    SYMPTOMS

;

    rounded palpebral fissures
    SYMPTOMS

;

    esotropia
    SYMPTOMS

;

    wide, flattened earlobes
    SYMPTOMS

; and a

    downturned mouth
    SYMPTOMS

. The combination of medical history and

    characteristic facies
    SYMPTOMS

 should prompt the request for specific laboratory tests diagnostic for this potentially treatable condition.

Complex glycerol kinase deficiency
Duchenne muscular dystrophy


Duchenne muscular dystrophy presenting with failure to thrive.

Three patients with Duchenne muscular dystrophy presenting with failure to thrive in infancy are described. Their families noted poor growth and sought medical advice up to six months before the diagnosis was suspected. Growth charts showed weight loss between 4 and 18 months of age. Length growth was affected while growth in head circumference remained unaffected. No causes of failure to thrive were found at presentation. Failure to thrive in Duchenne muscular dystrophy has been described previously but it is neither widely recognised nor understood. Poor growth in the first years and eventual short stature, however, is a well described feature of Duchenne muscular dystrophy. Failure to thrive in our three patients may be an extreme manifestation of this.

Three patients with

    Duchenne muscular dystrophy
    DIAGNOSIS

 presenting with

    failure to thrive
    SYMPTOMS

 in

    infancy
    AGE

 are described. Their families noted

    poor growth
    SYMPTOMS

 and sought medical advice up to six months before the diagnosis was suspected.

    Growth charts
    PARACLINICAL

 showed

    weight loss
    SYMPTOMS

    between 4 and 18 months of age
    AGE

.

    Length growth was affected
    SYMPTOMS

 while

    growth in head circumference remained unaffected
    NEG_FINDINGS

.

    No causes of failure to thrive were found
    NEG_FINDINGS

 at presentation.

    Failure to thrive
    SYMPTOMS

 in

    Duchenne muscular dystrophy
    DIAGNOSIS

 has been described previously but it is neither widely recognised nor understood.

    Poor growth in the first years
    SYMPTOMS

 and

    eventual short stature
    SYMPTOMS

, however, is a well described feature of

    Duchenne muscular dystrophy
    DIAGNOSIS

.

    Failure to thrive
    SYMPTOMS

 in our three patients may be an extreme manifestation of this.

Duchenne muscular dystrophy
Duchenne muscular dystrophy
Duchenne muscular dystrophy

failure to thrive
poor growth
weight loss
Length growth was affected
Failure to thrive
Poor growth in the first years
eventual short stature
Failure to thrive


A carrier of Duchenne muscular dystrophy with dilated cardiomyopathy but no skeletal muscle symptom.

A 29-year-old female developed dilated cardiomyopathy at 20 years of age but with no muscle symptoms. Her 2-year-old son with Duchenne muscular dystrophy (DMD)_had no demonstrable deletion in the dystrophin gene, but all fibers except for 5% 'revertant' fibers in a muscle biopsy specimen had no dystrophin. Both skeletal and cardiac muscle biopsy specimens from the mother showed a mosaic distribution of dystrophin-positive and -negative fibers, and so she was diagnosed as being a manifesting carrier of DMD. We conclude that, when one encounters a female patient with idiopathic cardiomyopathy with a high serum creatine kinase level, the suspicion of her being a manifesting DMD carrier should be ruled out.

A

    29-year-old
    AGE

    female
    GENDER

 developed

    dilated cardiomyopathy
    DIAGNOSIS

 at

    20 years of age
    AGE

 but with

    no muscle symptoms
    NEG_FINDINGS

.

    Her
    GENDER

 2-year-old son with Duchenne muscular dystrophy (DMD)_had

    no demonstrable deletion in the dystrophin gene
    NEG_FINDINGS

, but

    all fibers except for 5% 'revertant' fibers in a muscle biopsy specimen
    MICROSCOPIC

    had no dystrophin
    MICROSCOPIC

. Both

    skeletal and cardiac muscle biopsy specimens
    PARACLINICAL

 from the mother showed a

    mosaic distribution of dystrophin-positive and -negative fibers
    MICROSCOPIC

, and so

    she
    GENDER

 was diagnosed as being a

    manifesting carrier of DMD
    FAMILY

. We conclude that, when one encounters a

    female
    GENDER

 patient with

    idiopathic cardiomyopathy
    DIAGNOSIS

 with a

    high serum creatine kinase level
    BIOCHEMICAL

, the suspicion of

    her
    GENDER

 being a

    manifesting DMD carrier
    NEG_FINDINGS

 should be ruled out.

dilated cardiomyopathy
idiopathic cardiomyopathy


Genetic and biochemical normalization in female carriers of Duchenne muscular dystrophy: evidence for failure of dystrophin production in dystrophin-competent myonuclei.

We studied 19 symptomatic female carriers of the Duchenne muscular dystrophy (DMD) gene. Most of these dystrophinopathy patients had had an erroneous or ambiguous diagnosis prior to dystrophin immunofluorescence testing. We assessed clinical severity by a standardized protocol, measured X-chromosome inactivation patterns in blood and muscle DNA, and quantitated the dystrophin protein content of muscle. We found that patients could be separated into two groups: those showing equal numbers of normal and mutant dystrophin genes in peripheral blood DNA ("random" X-inactivation), and those showing preferential use of the mutant dystrophin gene ("skewed" X-inactivation). In the random X-inactivation carriers, the clinical phenotype ranged from asymptomatic to mild disability, the dystrophin content of muscle was > 60% of normal, and there were only minor histopathologic changes. In the skewed X-inactivation patients, clinical manifestations ranged from mild to severe, but the patients with mild disease were young (5 to 10 years old). The low levels of dystrophin (< 30% on average) and the severe symptoms of the older patients suggested a poor prognosis for those with skewed X-inactivation, and they all showed morphologic changes of dystrophy. The random inactivation patients showed evidence of biochemical "normalization," with higher dystrophin content in muscle than predicted by the number of normal dystrophin genes. Seventy-nine percent of skewed X-inactivation patients (11/14) showed genetic "normalization," with proportionally more dystrophin-positive nuclei in muscle than in blood. In 65% of the skewed X-inactivation patients, dystrophin was not produced by dystrophin-positive nuclei; an average of 20% of myofiber nuclei were genetically dystrophin-positive but did not produce stable dystrophin. Biochemical normalization seems to be the main mechanism for rescue of fibers from dystrophin deficiency in the random X-inactivation patients. In the skewed X-inactivation patients, genetic normalization is active, but production failure of dystrophin by dystrophin-normal nuclei may counteract any effect of biochemical normalization. In the skewed X-inactivation patients, the remodeling of the muscle through cycles of degeneration and regeneration led to threefold increase in the number of dystrophin-competent nuclei in muscle myofibers (3.3 +/- 4.6), while dystrophin content was on the average 1.5-fold less then expected (-1.54 +/- 3.38). Our results permit more accurate prognistic assessment of isolated female dystrophinopathy patients and provide important data with which to estimate the potential effect of gene delivery (gene therapy) in DMD.

We studied 19 symptomatic

    female
    GENDER

 carriers of the

    Duchenne muscular dystrophy (DMD) gene
    DIAGNOSIS

. Most of these

    dystrophinopathy
    DIAGNOSIS

 patients had had an

    erroneous or ambiguous diagnosis
    NEG_FINDINGS

 prior to

    dystrophin immunofluorescence testing
    PARACLINICAL

. We assessed clinical severity by a standardized protocol,

    measured X-chromosome inactivation patterns in blood and muscle DNA
    PARACLINICAL

, and

    quantitated the dystrophin protein content of muscle
    PARACLINICAL

. We found that patients could be separated into two groups: those showing

    equal numbers of normal and mutant dystrophin genes in peripheral blood DNA
    GENETICS

 ("

    random" X-inactivation
    GENETICS

    )
    GENETICS

, and those showing

    preferential use of the mutant dystrophin gene
    GENETICS

 (

    "skewed" X-inactivation)
    GENETICS

. In the

    random X-inactivation
    GENETICS

 carriers, the clinical phenotype ranged from

    asymptomatic to mild disability
    SYMPTOMS

, the

    dystrophin content of muscle was > 60% of normal
    BIOCHEMICAL

, and there were

    only minor histopathologic changes
    SYMPTOMS

. In the

    skewed X-inactivation
    GENETICS

 patients,

    clinical manifestations ranged from mild to severe
    SYMPTOMS

, but the patients with

    mild disease
    DIAGNOSIS

 were

    young
    AGE

    (5 to 10 years old)
    AGE

. The

    low levels of dystrophin (< 30% on average)
    BIOCHEMICAL

 and the

    severe symptoms
    SYMPTOMS

 of the

    older
    AGE

 patients suggested a poor prognosis for those with

    skewed X-inactivation
    GENETICS

, and they all showed

    morphologic changes of dystrophy
    SYMPTOMS

. The

    random inactivation
    GENETICS

 patients showed evidence of

    biochemical "normalization
    SYMPTOMS

," with

    higher dystrophin content in muscle
    BIOCHEMICAL

 than predicted by the

    number of normal dystrophin genes
    BIOCHEMICAL

. Seventy-nine percent of

    skewed X-inactivation
    GENETICS

 patients (11/14) showed

    genetic "normalization
    SYMPTOMS

," with

    proportionally more dystrophin-positive nuclei in muscle than in blood
    MICROSCOPIC

. In 65% of the

    skewed X-inactivation
    GENETICS

 patients,

    dystrophin was not produced by dystrophin-positive nuclei
    MICROSCOPIC

; an

    average of 20% of myofiber nuclei were genetically dystrophin-positive but did not produce stable dystrophin
    MICROSCOPIC

.

    Biochemical normalization
    SYMPTOMS

 seems to be the main mechanism for

    rescue of fibers from dystrophin deficiency
    MICROSCOPIC

 in the

    random X-inactivation
    GENETICS

 patients. In the

    skewed X-inactivation
    GENETICS

 patients,

    genetic normalization
    GENETICS

 is active, but

    production failure of dystrophin by dystrophin-normal nuclei
    MICROSCOPIC

 may

    counteract any effect of biochemical normalization
    NEG_FINDINGS

. In the

    skewed X-inactivation
    GENETICS

 patients, the

    remodeling of the muscle
    MICROSCOPIC

 through

    cycles of degeneration and regeneration
    SYMPTOMS

 led to

    threefold increase in the number of dystrophin-competent nuclei in muscle myofibers (3.3 +/- 4.6)
    MICROSCOPIC

, while

    dystrophin content was on the average 1.5-fold less then expected (-1.54 +/- 3.38)
    BIOCHEMICAL

. Our results permit more accurate prognistic assessment of isolated

    female
    GENDER

    dystrophinopathy
    DIAGNOSIS

 patients and provide important data with which to estimate the potential effect of

    gene delivery (gene therapy)
    MEDICATION

 in

    DMD
    DIAGNOSIS

.

Duchenne muscular dystrophy (DMD) gene
dystrophinopathy
mild disease
dystrophinopathy
DMD


In utero fetal muscle biopsy alters diagnosis and carrier risks in Duchenne and Becker muscular dystrophy.

We have previously shown that Duchenne muscular dystrophy (DMD) can be diagnosed by fetal muscle biopsy and immunohistochemical staining showing the absence of dystrophin. In Becker muscular dystrophy (BMD), there is a variable dystrophin staining pattern.

A 26-year-old, gravida 5, para 1, SAB 2, VIP 1, white female had a son with the diagnosis of BMD, with no other affected family members. In the current pregnancy, the male fetus inherited the same X chromosome.

Fetal muscle biopsy revealed no dystrophin, consistent with the diagnosis of DMD, prompting re-analysis of the sibling whose diagnosis was then changed to DMD.

Molecular techniques in prenatal diagnosis in this case not only led to the diagnosis of a severe disorder in the current pregnancy, but changed the diagnosis in another child, allowing for more appropriate counseling of this couple.

We have previously shown that

    Duchenne muscular dystrophy (DMD)
    DIAGNOSIS

 can be diagnosed by

    fetal muscle biopsy
    PARACLINICAL

 and

    immunohistochemical staining
    PARACLINICAL

 showing the

    absence of dystrophin
    BIOCHEMICAL

. In

    Becker muscular dystrophy (BMD)
    DIAGNOSIS

, there is a

    variable dystrophin staining pattern
    SYMPTOMS

.

A

    26-year-old
    AGE

,

    gravida 5
    FAMILY

,

    para 1, SAB 2, VIP 1
    FAMILY

,

    white
    ETHNICITY

    female
    GENDER

    had a son with the diagnosis of BMD, with no other affected family members
    FAMILY

. In the current

    pregnancy
    DIAGNOSIS

, the

    male fetus inherited the same X chromosome
    FAMILY

.

    Fetal muscle biopsy
    PARACLINICAL

 revealed

    no dystrophin
    NEG_FINDINGS

, consistent with the diagnosis of

    DMD
    DIAGNOSIS

, prompting

    re-analysis of the sibling whose diagnosis was then changed to DMD
    PARACLINICAL

.

    Molecular techniques in prenatal diagnosis
    PARACLINICAL

 in this case not only led to the diagnosis of a

    severe disorder
    DIAGNOSIS

 in the current

    pregnancy
    DIAGNOSIS

, but changed the diagnosis in another child, allowing for more appropriate counseling of this couple.

Duchenne muscular dystrophy (DMD)
Becker muscular dystrophy (BMD)
pregnancy
DMD
severe disorder
pregnancy


[Complete deficiency of adhalin (50 kDa DAG) in skeletal muscle of malignant limb-girdle muscular dystrophy].

Malignant limb-girdle muscular dystrophy was first described by Miyoshi and co-workers in 1966, and has clinical features similar to Duchenne muscular dystrophy but is inherited through an autosomal recessive trait. This paper describes a patient with malignant limb-girdle muscular dystrophy with complete deficiency of adhalin (50 kDa dystrophin-associated glycoprotein (DAG)) in skeletal muscle. The patient was an 11-year-old Japanese girl whose parents were cousin. She learned to walk at one year and 3 months of age. Her gait became unsteady at 3 years of age, and motor dysfunction in the lower extremities progressed thereafter. At 8 years of age, she had difficulty in standing up from a sitting position, but could walk without assistance. At 11 years, she could walk with support, but could not stand up without assistance. Her intelligence was normal. Muscle atrophy was not apparent due to obesity, but her calves appeared hypertrophic. She had generalized muscle weakness, predominantly in the pelvic girdle muscle. Muscle tone was slightly hypotonic, and deep tendon reflexes of the legs were absent or hypoactive. Her sensory system appeared normal. Serum creatine kinase level was elevated to 30 times above the upper limit of the normal range in the patient and normal in her parents. EMG showed a mild myopathic pattern. CT scan of muscle revealed marked low density in the upper legs and mild in the lower legs. Muscle histology showed muscle fiber necrosis with a small number of regenerating fibers. Opaque fibers were occasionally observed, but not as many as in Duchenne type. Fiber splitting was seen frequently.(ABSTRACT TRUNCATED AT 250 WORDS)

    Malignant limb-girdle muscular dystrophy
    DIAGNOSIS

 was first described by Miyoshi and co-workers in 1966, and has clinical features similar to

    Duchenne muscular dystrophy
    DIAGNOSIS

 but is

    inherited through an autosomal recessive trait
    GENETICS

. This paper describes a patient with

    malignant limb-girdle muscular dystrophy
    DIAGNOSIS

 with

    complete deficiency of adhalin (50 kDa dystrophin-associated glycoprotein (DAG)) in skeletal muscle
    BIOCHEMICAL

. The patient was an

    11-year-old
    AGE

    Japanese
    ETHNICITY

    girl
    GENDER

    whose parents were cousin
    FAMILY

.

    She
    GENDER

 learned to walk

    at one year and 3 months of age
    AGE

.

    Her
    GENDER

    gait became unsteady
    SYMPTOMS

    at 3 years of age
    AGE

, and

    motor dysfunction in the lower extremities
    SYMPTOMS

 progressed thereafter.

    At 8 years of age
    AGE

,

    she
    GENDER

 had

    difficulty in standing up from a sitting position
    NEG_FINDINGS

, but

    could walk without assistance
    NEG_FINDINGS

.

    At 11 years
    AGE

,

    she
    GENDER

    could walk with support
    NEG_FINDINGS

, but

    could not stand up without assistance
    NEG_FINDINGS

.

    Her
    GENDER

    intelligence was normal
    NEG_FINDINGS

.

    Muscle atrophy
    SYMPTOMS

    was not apparent
    NEG_FINDINGS

 due to

    obesity
    NEG_FINDINGS

, but

    her
    GENDER

    calves appeared hypertrophic
    SYMPTOMS

.

    She
    GENDER

 had

    generalized muscle weakness, predominantly in the pelvic girdle muscle
    SYMPTOMS

.

    Muscle tone was slightly hypotonic
    SYMPTOMS

, and

    deep tendon reflexes of the legs were absent or hypoactive
    NEG_FINDINGS

.

    Her
    GENDER

    sensory system appeared normal
    NEG_FINDINGS

.

    Serum creatine kinase level was elevated to 30 times above the upper limit of the normal range
    BIOCHEMICAL

 in the patient and

    normal in her parents
    NEG_FINDINGS

.

    EMG
    PARACLINICAL

 showed a

    mild myopathic pattern
    SYMPTOMS

.

    CT scan of muscle
    PARACLINICAL

 revealed

    marked low density in the upper legs and mild in the lower legs
    SYMPTOMS

.

    Muscle histology
    PARACLINICAL

 showed

    muscle fiber necrosis with a small number of regenerating fibers
    MICROSCOPIC

.

    Opaque fibers
    MICROSCOPIC

 were occasionally observed, but not as many as in

    Duchenne type
    DIAGNOSIS

.

    Fiber splitting
    MICROSCOPIC

 was seen frequently.(ABSTRACT TRUNCATED AT 250 WORDS)


Duchenne muscular dystrophy and myotonic dystrophy in the same patient.

We report on the first patient identified with myotonic dystrophy and Duchenne muscular dystrophy (DMD). The family of the propositus had a strong history of myotonic dystrophy, and there was an intrafamilial pathological expansion of the responsible CTG repeat between the mildly affected mother (160 repeats; normal 27 repeats) and her more severely affected son (650 repeats), and his sister (650 repeats). The propositus was an isolated case of Duchenne muscular dystrophy with marked dystrophin deficiency in muscle biopsy. The patient was still ambulatory post age 16. Myotonic dystrophy could interfere to some extent with the progression of Duchenne dystrophy. However, other interpretations are possible. Twelve percent of dystrophin revertant fibers as observed by immunohistochemistry could be sufficient to ameliorate typical DMD clinical severity, or the patient may present a somatic mosaic. The pathophysiological interactions of these two unlinked disorders are discussed at the clinical and histopathological levels.

We report on the first patient identified with

    myotonic dystrophy and Duchenne muscular dystrophy (DMD)
    DIAGNOSIS

. The

    family of the propositus had a strong history of myotonic dystrophy
    FAMILY

, and there was

    an intrafamilial pathological expansion of the responsible CTG repeat between the mildly affected mother (160 repeats; normal 27 repeats) and her more severely affected son (650 repeats), and his sister (650 repeats)
    GENETICS

. The

    propositus was an isolated case of Duchenne muscular dystrophy
    FAMILY

 with

    marked dystrophin deficiency
    BIOCHEMICAL

    in muscle biopsy
    SYMPTOMS

. The patient was

    still ambulatory
    MEDICATION

    post age 16
    AGE

.

    Myotonic dystrophy
    DIAGNOSIS

 could interfere to some extent with the progression of

    Duchenne dystrophy
    DIAGNOSIS

. However, other interpretations are possible.

    Twelve percent of dystrophin revertant fibers
    MICROSCOPIC

 as observed by

    immunohistochemistry
    PARACLINICAL

 could be sufficient to

    ameliorate typical DMD clinical severity
    SYMPTOMS

, or the patient may present a

    somatic mosaic
    GENETICS

. The pathophysiological interactions of these two unlinked disorders are discussed at the clinical and histopathological levels.


[A case of severe Becker muscular dystrophy diagnosed in early childhood--correlation between clinical severity and dystrophin testing].

Since the 14kb human Duchenne muscular dystrophy (DMD) cDNA was cloned and its protein product "dystrophin" was discovered, immunochemical, biochemical and genetic analyses of dystrophin (dystrophin testing) have provided an accurate diagnosis of DMD/Becker muscular dystrophy in the clinical field. We performed dystrophin testing for a 5-year-old boy and confirmed he had severe BMD. Multiplex PCR of the DMD gene showed in-frame type deletion from exon 45 to 48. Immunohistochemical analysis of the muscle specimen obtained from the patient showed a discontinuous and patchy staining pattern, using monoclonal antibody that recognizes the C-terminus domain of dystrophin. On immunoblot analysis, we detected a faint band of 390 kDa. Dystrophin quantity was less than 10% of that compared to normal controls. The correlation between clinical severity and dystrophin testing was discussed.

Since the

    14kb human Duchenne muscular dystrophy (DMD)
    GENETICS

 cDNA was cloned and its protein product "dystrophin" was discovered,

    immunochemical, biochemical and genetic analyses of dystrophin
    PARACLINICAL

 (

    dystrophin testing
    PARACLINICAL

) have provided an accurate diagnosis of

    DMD/Becker muscular dystrophy
    DIAGNOSIS

 in the clinical field. We performed

    dystrophin testing
    PARACLINICAL

 for a

    5-year-old
    AGE

    boy
    GENDER

 and confirmed

    he
    GENDER

 had

    severe BMD
    DIAGNOSIS

.

    Multiplex PCR of the DMD gene
    PARACLINICAL

 showed

    in-frame type deletion from exon 45 to 48
    GENETICS

.

    Immunohistochemical analysis of the muscle specimen
    PARACLINICAL

 obtained from the patient showed a

    discontinuous and patchy staining pattern
    MICROSCOPIC

, using monoclonal antibody that recognizes the

    C-terminus domain of dystrophin
    BIOCHEMICAL

. On

    immunoblot analysis
    PARACLINICAL

, we detected a

    faint band of 390 kDa
    BIOCHEMICAL

.

    Dystrophin quantity was less than 10% of that compared to normal controls
    BIOCHEMICAL

. The correlation between clinical severity and

    dystrophin testing
    PARACLINICAL

 was discussed.

DMD/Becker muscular dystrophy
severe BMD


[Congenital adrenal gland insufficiency and myopathy].

We report a rare case of a female newborn presenting with muscular hypotonia, pneumonia, and cardiovascular and renal insufficiency. Adrenal insufficiency was diagnosed clinically and proven by extremely low cortisone (0.4-0.8 microgram/dl) and high ACTH plasma levels. Myopathy was diagnosed clinically, as well as by muscular biopsy. DNA analysis of both X chromosomes showed no abnormality in the region of the genes for adrenal hypoplasia and Duchenne muscular dystrophy. After 4 weeks of intensive care therapy the patient died of multiorgan failure. At autopsy she had only microscopically visible fetal adrenal cells and multiple porencephalic lesions.

We report a rare case of a

    female
    GENDER

    newborn
    AGE

 presenting with

    muscular hypotonia
    SYMPTOMS

,

    pneumonia
    SYMPTOMS

, and

    cardiovascular and renal insufficiency
    SYMPTOMS

.

    Adrenal insufficiency
    SYMPTOMS

 was diagnosed clinically and proven by

    extremely low cortisone (0.4-0.8 microgram/dl) and high ACTH plasma levels
    BIOCHEMICAL

.

    Myopathy
    DIAGNOSIS

 was diagnosed clinically, as well as by

    muscular biopsy
    PARACLINICAL

.

    DNA analysis of both X chromosomes
    PARACLINICAL

 showed

    no abnormality in the region of the genes for adrenal hypoplasia and Duchenne muscular dystrophy
    NEG_FINDINGS

.

    After 4 weeks of intensive care therapy
    MEDICATION

 the patient

    died
    SYMPTOMS

 of

    multiorgan failure
    SYMPTOMS

. At

    autopsy
    PARACLINICAL

    she
    GENDER

 had

    only microscopically visible fetal adrenal cells
    MICROSCOPIC

 and

    multiple porencephalic lesions
    SYMPTOMS

.

muscular hypotonia
pneumonia
cardiovascular and renal insufficiency
Adrenal insufficiency
died
multiorgan failure
multiple porencephalic lesions


[Diagnostic problems of congenital muscular dystrophies in children].

Three children with a diagnosis of congenital muscular dystrophy are described. Because of the heterogeneity of these disorders the authors stress the necessity of differentiation with other causes of "floppy infant" syndrome, especially with Werdnig-Hoffmann disease, structural myopathies, and Duchenne progressive muscular dystrophy. An extensive hypodense area on brain CT scan was found in one child.

Three

    children
    AGE

 with a diagnosis of

    congenital muscular dystrophy
    DIAGNOSIS

 are described. Because of the heterogeneity of these disorders the authors stress the necessity of differentiation with other causes of "

    floppy infant" syndrome
    SYMPTOMS

, especially with

    Werdnig-Hoffmann disease
    DIAGNOSIS

,

    structural myopathies
    DIAGNOSIS

, and

    Duchenne progressive muscular dystrophy
    DIAGNOSIS

. An

    extensive hypodense area on brain CT scan
    SYMPTOMS

 was found in one

    child
    AGE

.

congenital muscular dystrophy
Werdnig-Hoffmann disease
structural myopathies
Duchenne progressive muscular dystrophy


[Propofol in Duchenne muscular dystrophy].

The authors used propofol in continuous infusion (4 mg x kg-1 x h) fentanyl, O2/N2O in CMW without any myorelaxant in a 11-year-old patient with Duchenne's muscular dystrophy. This anesthesia technique proved to be safe and handy; allowing a nearly postoperative recovery of state of coscience; and ventilatory autonomy; without any cardio-vascular complication.

The authors used

    propofol in continuous infusion (4 mg x kg-1 x h) fentanyl, O2/N2O in CMW
    MEDICATION

    without any myorelaxant
    NEG_FINDINGS

 in a

    11-year-old
    AGE

 patient with

    Duchenne's muscular dystrophy
    DIAGNOSIS

. This

    anesthesia technique
    MEDICATION

 proved to be safe and handy; allowing a

    nearly postoperative recovery of state of coscience
    SYMPTOMS

; and

    ventilatory autonomy
    SYMPTOMS

;

    without any cardio-vascular complication
    NEG_FINDINGS

.


Immunohistochemistry in the diagnosis of dystrophinopathies.

Sixty-four muscle biopsies obtained from patients with Duchenne muscular dystrophy, limb-girdle dystrophy, congenital muscular dystrophy, or who referred for diagnosis were examined with histochemical methods for dystrophin staining with antidystrophin antibodies. Six atypical cases in whom the dystrophin expression was inconsistent with both clinical and morphopathological pattern were selected: one case of Duchenne muscular dystrophy in whom dystrophin was partially represented, one case referred for investigation in whom dystrophin was absent, despite the lack of clinico-morphological signs supporting the diagnosis of Duchenne disease, two cases of congenital muscular dystrophy in whom dystrophin was absent and one patient with the same diagnosis in whom dystrophin was present, but quantitatively reduced. A patient with limb-girdle muscle dystrophy, in whom immunohistochemical investigation was necessary for the diagnosis is also reported. In conclusion, the immunohistochemical investigation using antidystrophin labelled antibodies of muscle biopsies obtained from patients with various types of muscular dystrophy is mandatory.

Sixty-four

    muscle biopsies
    PARACLINICAL

 obtained from patients with

    Duchenne muscular dystrophy
    DIAGNOSIS

,

    limb-girdle dystrophy
    DIAGNOSIS

,

    congenital muscular dystrophy
    DIAGNOSIS

, or who referred for diagnosis were examined with

    histochemical methods for dystrophin staining with antidystrophin antibodies
    PARACLINICAL

. Six atypical cases in whom the

    dystrophin expression was inconsistent with both clinical and morphopathological pattern
    SYMPTOMS

 were selected: one case of

    Duchenne muscular dystrophy
    DIAGNOSIS

 in whom

    dystrophin was partially represented
    BIOCHEMICAL

, one case referred for investigation in whom

    dystrophin was absent
    NEG_FINDINGS

,

    despite the lack of clinico-morphological signs supporting the diagnosis of Duchenne disease
    NEG_FINDINGS

, two cases of

    congenital muscular dystrophy
    DIAGNOSIS

 in whom

    dystrophin was absent
    BIOCHEMICAL

 and one patient with the same diagnosis in whom

    dystrophin was present, but quantitatively reduced
    BIOCHEMICAL

. A patient with

    limb-girdle muscle dystrophy
    DIAGNOSIS

, in whom

    immunohistochemical investigation
    PARACLINICAL

 was necessary for the diagnosis is also reported. In conclusion, the

    immunohistochemical investigation using antidystrophin labelled antibodies of muscle biopsies
    PARACLINICAL

 obtained from patients with various types of

    muscular dystrophy
    DIAGNOSIS

 is mandatory.

Duchenne muscular dystrophy
limb-girdle dystrophy
congenital muscular dystrophy
Duchenne muscular dystrophy
congenital muscular dystrophy
limb-girdle muscle dystrophy
muscular dystrophy


Polymerase chain reaction fiber analysis and somatic mosaicism in autopsied tissue from a man with Duchenne muscular dystrophy.

Single muscle fibers, obtained at autopsy from a 22-year-old man with Duchenne muscular dystrophy were examined immunocytochemically and also using polymerase chain reaction (PCR). Dystrophin-positive cells were widespread in skeletal, cardiac, smooth muscle, and in brain cells. PCR and Southern blot analyses of DNA from peripheral blood lymphocytes revealed a deletion of exon 45 in the dystrophin gene. With PCR of single fibers, three bands corresponding to exons 44, 45, and 47 were present in the normal control muscle fibers and dystrophin-positive fibers from the patient, while only two bands, exons 44 and 47, were observed in dystrophin-negative fibers. Therefore, in this patient, the genotype of dystrophin-positive fibers differed from that of the dystrophin-negative fibers, possibly because of a somatic mosaicism for deletion in the dystrophin gene. A mutation of the dystrophin gene may have occurred in one cell at an early stage of ontogenesis.

    Single muscle fibers
    MICROSCOPIC

, obtained at

    autopsy
    PARACLINICAL

 from a

    22-year-old
    AGE

    man
    GENDER

 with

    Duchenne muscular dystrophy
    DIAGNOSIS

 were examined

    immunocytochemically
    PARACLINICAL

 and also using

    polymerase chain reaction (PCR)
    PARACLINICAL

.

    Dystrophin-positive cells were widespread in skeletal, cardiac, smooth muscle, and in brain cells
    MICROSCOPIC

.

    PCR and Southern blot analyses of DNA from peripheral blood lymphocytes
    PARACLINICAL

 revealed a

    deletion of exon 45 in the dystrophin gene
    GENETICS

. With

    PCR of single fibers
    PARACLINICAL

,

    three bands corresponding to exons 44, 45, and 47
    GENETICS

 were present in the

    normal control muscle fibers
    SYMPTOMS

 and

    dystrophin-positive fibers
    MICROSCOPIC

 from the patient, while only two bands

    , exons 44 and 47
    GENETICS

, were observed in

    dystrophin-negative fibers
    SYMPTOMS

. Therefore, in this patient, the

    genotype of dystrophin-positive fibers differed from that of the dystrophin-negative fibers
    SYMPTOMS

, possibly because of a

    somatic mosaicism for deletion in the dystrophin gene
    GENETICS

. A

    mutation of the dystrophin gene
    GENETICS

 may have occurred in one cell at an early stage of ontogenesis.


Congenital adrenal hypoplasia, Duchenne muscular dystrophy, and glycerol kinase deficiency: importance of laboratory investigations in delineating a contiguous gene deletion syndrome.

We describe an infant with adrenal insufficiency who was subsequently diagnosed with Duchenne muscular dystrophy (DMD) and hyperglycerolemia due to glycerol kinase deficiency. Karyotyping showed a deletion on the short arm of the X chromosome (p21.1 to p22.1). Molecular mapping revealed that the deletion extended from the 3' end of the DMD gene to a site telomeric to the loci for X-linked congenital adrenal hypoplasia and glycerol kinase deficiency. These results are diagnostic for an Xp21 contiguous gene deletion syndrome--so named because the deletion manifests as a distinctive cluster of otherwise unrelated single-gene disorders in the same individual. The Xp21 syndrome should be considered in any infant with adrenal insufficiency. Measurement of serum triglycerides (without glycerol blanking) and creatine kinase activity are simple screening tests that may facilitate early diagnosis and appropriate genetic counseling about risks of recurrence in subsequent offspring.

We describe an

    infant
    AGE

 with

    adrenal insufficiency
    SYMPTOMS

 who was subsequently diagnosed with

    Duchenne muscular dystrophy (DMD)
    DIAGNOSIS

 and

    hyperglycerolemia
    BIOCHEMICAL

 due to

    glycerol kinase deficiency
    BIOCHEMICAL

.

    Karyotyping
    PARACLINICAL

 showed a

    deletion on the short arm of the X chromosome (p21.1 to p22.1)
    GENETICS

.

    Molecular mapping
    PARACLINICAL

 revealed that the

    deletion extended from the 3' end of the DMD gene to a site telomeric to the loci for X-linked congenital adrenal hypoplasia
    GENETICS

 and

    glycerol kinase deficiency
    BIOCHEMICAL

. These results are diagnostic for an

    Xp21 contiguous gene deletion syndrome
    GENETICS

--so named because the deletion manifests as a

    distinctive cluster of otherwise unrelated single-gene disorders
    SYMPTOMS

 in the same individual. The

    Xp21 syndrome
    DIAGNOSIS

 should be considered in any

    infant
    AGE

 with

    adrenal insufficiency
    SYMPTOMS

.

    Measurement of serum triglycerides (without glycerol blanking
    PARACLINICAL

) and

    creatine kinase activity
    BIOCHEMICAL

 are simple screening tests that may facilitate early diagnosis and appropriate genetic counseling about risks of recurrence in subsequent offspring.

Duchenne muscular dystrophy (DMD)
Xp21 syndrome

hyperglycerolemia
glycerol kinase deficiency
glycerol kinase deficiency
creatine kinase activity


A new nonsyndromic X-linked sensorineural hearing impairment linked to Xp21.2.

X-linked deafness is a rare cause of hereditary hearing impairment. We have identified a family with X-linked dominant sensorineural hearing impairment, characterized by incomplete penetrance and variable expressivity in carrier females, that is linked to the Xp21.2, which contains the Duchenne muscular dystrophy (DMD) locus. The auditory impairment in affected males was congenital, bilateral, profound, sensorineural, affecting all frequencies, and without evidence of radiographic abnormality of the temporal bone. Adult carrier females manifested bilateral, mild-to-moderate high-frequency sensorineural hearing impairment of delayed onset during adulthood. Eighteen commercially available, polymorphic markers from the X chromosome, generating a 10-15-cM map, were initially used for identification of a candidate region. DXS997, located within the DMD gene, generated a two-point LOD score of 2.91 at theta = 0, with every carrier mother heterozygous at this locus. Recombination events at DXS992 (located within the DMD locus, 3' to exon 50 of the dystrophin gene) and at DXS1068 (5' to the brain promoter of the dystrophin gene) were observed. No recombination events were noted with the following markers within the DMD locus: 5'DYS II, intron 44, DXS997, and intron 50. There was no clinical evidence of Duchenne or Becker muscular dystrophy in any family member. It is likely that this family represents a new locus on the X chromosome, which when mutated results in nonsyndromic sensorineural hearing loss and is distinct from the heterogeneous group of X-linked hearing losses that have been previously described.

    X-linked deafness
    GENETICS

 is a rare cause of

    hereditary hearing impairment
    GENETICS

. We have identified a family with

    X-linked dominant sensorineural hearing impairment
    GENETICS

, characterized by

    incomplete penetrance
    SYMPTOMS

 and variable expressivity in carrier

    females
    GENDER

, that is linked to the

    Xp21.2, which contains the Duchenne muscular dystrophy (DMD) locus
    GENETICS

. The

    auditory impairment
    SYMPTOMS

 in affected

    males
    GENDER

 was

    congenital, bilateral, profound, sensorineural, affecting all frequencies
    SYMPTOMS

, and

    without evidence of radiographic abnormality of the temporal bone
    NEG_FINDINGS

.

    Adult
    AGE

 carrier

    females
    GENDER

 manifested

    bilateral, mild-to-moderate high-frequency sensorineural hearing impairment
    SYMPTOMS

 of

    delayed onset
    SYMPTOMS

    during adulthood
    AGE

. Eighteen commercially available,

    polymorphic markers from the X chromosome
    PARACLINICAL

, generating a 10-15-cM map, were initially used for identification of a candidate region.

    DXS997, located within the DMD gene
    GENETICS

, generated a two-point LOD score of 2.91 at theta = 0, with every

    carrier mother heterozygous at this locus
    FAMILY

.

    Recombination events at DXS992 (located within the DMD locus, 3' to exon 50 of the dystrophin gene) and at DXS1068 (5' to the brain promoter of the dystrophin gene)
    GENETICS

 were observed.

    No recombination events were noted with the following markers within the DMD locus: 5'DYS II, intron 44, DXS997, and intron 50
    NEG_FINDINGS

. There was

    no clinical evidence of Duchenne or Becker muscular dystrophy in any family member
    NEG_FINDINGS

. It is likely that this family represents a

    new locus on the X chromosome
    GENETICS

, which when mutated results in

    nonsyndromic sensorineural hearing loss
    SYMPTOMS

 and is distinct from the heterogeneous group of

    X-linked hearing losses
    GENETICS

 that have been previously described.


Dilated cardiomyopathy and the dystrophin gene: an illustrated review.

Cardiomyopathy is often found in patients with Duchenne and Becker muscular dystrophy, which are X linked muscle diseases caused by mutations in the dystrophin gene. Dystrophin defects present in many different ways and cases of mild Becker muscular dystrophy have been described in which cardiomyopathy was severe. Female carriers of Duchenne muscular dystrophy can develop symptomatic skeletal myopathy alone or combined with dilated cardiomyopathy. They can also develop dilated cardiomyopathy alone. X linked dilated cardiomyopathy has been found in association with dystrophin defects. The relation between the molecular defects and the cardiac phenotypes has not yet been established. New mutations in the dystrophin gene are common and such mutations cause one third of the cases with Duchenne and Becker muscular dystrophy. This means that sporadic cases of cardiomyopathy caused by dystrophin defects are likely. This paper reports such a case in a boy of 14 who died of dilated cardiomyopathy. Before the cardiac investigation, which was performed one month before he died, he had not complained of muscular weakness. He had minor signs of limb girdle myopathy and slightly increased concentrations of serum creatine kinase. He was found to have an unusual deletion in the dystrophin gene.

    Cardiomyopathy
    DIAGNOSIS

 is often found in patients with

    Duchenne
    DIAGNOSIS

 and

    Becker muscular dystrophy
    DIAGNOSIS

, which are

    X linked
    GENETICS

    muscle diseases
    DIAGNOSIS

 caused by

    mutations in the dystrophin gene
    GENETICS

.

    Dystrophin defects
    GENETICS

 present in many different ways and cases of

    mild Becker muscular dystrophy
    DIAGNOSIS

 have been described in which

    cardiomyopathy
    SYMPTOMS

 was severe.

    Female
    GENDER

 carriers of

    Duchenne muscular dystrophy
    DIAGNOSIS

 can develop

    symptomatic skeletal myopathy
    SYMPTOMS

 alone or combined with

    dilated cardiomyopathy
    SYMPTOMS

. They can also develop

    dilated cardiomyopathy
    SYMPTOMS

 alone.

    X linked
    GENETICS

    dilated cardiomyopathy
    DIAGNOSIS

 has been found in association with

    dystrophin defects
    GENETICS

. The relation between the molecular defects and the cardiac phenotypes has not yet been established.

    New mutations in the dystrophin gene
    GENETICS

 are common and such mutations cause one third of the cases with

    Duchenne
    DIAGNOSIS

 and

    Becker muscular dystrophy
    DIAGNOSIS

. This means that sporadic cases of

    cardiomyopathy
    DIAGNOSIS

 caused by

    dystrophin defects
    GENETICS

 are likely. This paper reports such a case in a

    boy
    GENDER

 of

    14
    AGE

 who

    died
    SYMPTOMS

 of

    dilated cardiomyopathy
    DIAGNOSIS

. Before the

    cardiac investigation
    PARACLINICAL

, which was performed one month before

    he
    GENDER

    died
    SYMPTOMS

,

    he
    GENDER

 had

    not complained of muscular weakness
    NEG_FINDINGS

.

    He
    GENDER

 had

    minor signs of limb girdle myopathy
    SYMPTOMS

 and

    slightly increased concentrations of serum creatine kinase
    BIOCHEMICAL

.

    He
    GENDER

 was found to have an

    unusual deletion in the dystrophin gene
    GENETICS

.

Cardiomyopathy
Duchenne
Becker muscular dystrophy
muscle diseases
mild Becker muscular dystrophy
Duchenne muscular dystrophy
dilated cardiomyopathy
Duchenne
Becker muscular dystrophy
cardiomyopathy
dilated cardiomyopathy

X linked
mutations in the dystrophin gene
Dystrophin defects
X linked
dystrophin defects
New mutations in the dystrophin gene
dystrophin defects
unusual deletion in the dystrophin gene

cardiomyopathy
symptomatic skeletal myopathy
dilated cardiomyopathy
dilated cardiomyopathy
died
died
minor signs of limb girdle myopathy


Amino-terminal deletion of 53% of dystrophin results in an intermediate Duchenne-Becker muscular dystrophy phenotype.

We report a Japanese boy with muscular dystrophy whose clinical symptoms were intermediate between those usually considered typical of Duchenne and Becker muscular dystrophies. The patient had a large inframe deletion extending from exons 3 to 41 of the dystrophin gene, which would be expected to cause the production of a dystrophin protein composing only 53% of the normal polypeptide chain. Such an inframe deletion would be expected to cause Becker muscular dystrophy. We did not obtain evidence for alternative splicing or for RNA editing. Immunocytochemical analysis of skeletal muscle showed that a dystrophin-related polypeptide was detectable with antibody directed against the carboxyl-terminal part of the polypeptide but not with antibodies directed against the amino-terminal part, although labeling by antibody against the carboxyl-terminal was faint and patchy. The severity of the disease in this case may be due to the lack of the amino-terminal, actin-binding domain of dystrophin.

We report a

    Japanese
    ETHNICITY

    boy
    GENDER

 with

    muscular dystrophy
    DIAGNOSIS

 whose

    clinical symptoms were intermediate between those usually considered typical of Duchenne and Becker muscular dystrophies
    SYMPTOMS

. The patient had a

    large inframe deletion extending from exons 3 to 41 of the dystrophin gene
    GENETICS

, which would be expected to cause the production of a

    dystrophin protein composing only 53% of the normal polypeptide chain
    BIOCHEMICAL

. Such an

    inframe deletion
    GENETICS

 would be expected to cause

    Becker muscular dystrophy
    DIAGNOSIS

. We

    did not obtain evidence for alternative splicing or for RNA editing
    NEG_FINDINGS

.

    Immunocytochemical analysis of skeletal muscle
    PARACLINICAL

 showed that a

    dystrophin-related polypeptide was detectable
    BIOCHEMICAL

 with

    antibody directed against the carboxyl-terminal part of the polypeptide
    BIOCHEMICAL

 but

    not with antibodies directed against the amino-terminal part
    NEG_FINDINGS

, although labeling by antibody against the

    carboxyl-terminal was faint and patchy
    BIOCHEMICAL

. The severity of the disease in this case may be due to the

    lack of the amino-terminal, actin-binding domain of dystrophin
    BIOCHEMICAL

.

muscular dystrophy
Becker muscular dystrophy


Additional case of female monozygotic twins discordant for the clinical manifestations of Duchenne muscular dystrophy due to opposite X-chromosome inactivation.

A pair of female monozygotic (MZ) twins, heterozygous carriers for a deletion in the DMD gene and discordant for the clinical manifestations of Duchenne muscular dystrophy, were analyzed by molecular studies, in situ hybridization, and methylation pattern of X chromosomes to search for opposite X inactivation as an explanation of their clinical discordance. Results in lymphocytes and skin fibroblast cell lines suggest a partial mirror inactivation with the normal X chromosome preferentially active in the unaffected twin, and the maternal deleted X chromosome preferentially active in the affected twin. A review shows that MZ female twins discordant for X-linked diseases are not uncommon. Twinning and X inactivation may be interrelated and could explain the female twins discordant for X-linked traits.

A pair of

    female
    GENDER

    monozygotic (MZ) twins
    FAMILY

,

    heterozygous carriers for a deletion in the DMD gene
    GENETICS

 and

    discordant for the clinical manifestations of Duchenne muscular dystrophy
    FAMILY

, were analyzed by

    molecular studies
    PARACLINICAL

,

    in situ hybridization
    PARACLINICAL

, and

    methylation pattern of X chromosomes
    PARACLINICAL

 to search for

    opposite X inactivation
    GENETICS

 as an explanation of their clinical discordance. Results in

    lymphocytes and skin fibroblast cell lines
    MICROSCOPIC

 suggest a

    partial mirror inactivation with the normal X chromosome preferentially active in the unaffected twin, and the maternal deleted X chromosome preferentially active in the affected twin
    GENETICS

. A review shows that

    MZ female twins discordant for X-linked diseases
    FAMILY

 are not uncommon.

    Twinning
    FAMILY

 and

    X inactivation
    GENETICS

 may be interrelated and could explain the

    female
    GENDER

    twins discordant for X-linked traits
    FAMILY

.


Succinylcholine-induced cardiac arrest in children with undiagnosed myopathy.

Two paediatric cases are reported in which unexpected, life-threatening arrhythmias occurred. Routine induction of general anaesthesia with thiopentone, 5 mg.kg-1, in one and with halothane in the other, and succinylcholine 1.25-1.5 mg.kg-1 i.v. was followed by the development of wide complex tachyarrhythmia with hypotension in the first case and asystole in the second case despite pre-treatment with atropine in both cases. The first patient was resuscitated with tracheal intubation, 100% oxygen, manual ventilation and intravenous lidocaine and bicarbonate. The second patient required intubation, manual ventilation, 12 min of CPR and i.v. calcium, epinephrine and bicarbonate, as well as DC counter shock. Neither patient received dantrolene. Early recovery in both patients was uneventful with no neurological sequelae. Subsequent investigations revealed the presence of a dystrophin-deficient muscular dystrophy, Duchenne muscular dystrophy and Becker muscular dystrophy respectively, previously unsuspected, in both patients. The aetiology of the observed arrhythmias was presumably hyperkalaemia, secondary to succinylcholine-induced rhabdomyolysis. It is suggested that when faced with sudden, life-threatening arrhythmias following succinylcholine at induction of anaesthesia for paediatric patients, clinicians should include occult myopathy in the differential diagnosis, and thus consider the aggressive management of hyperkalaemia in addition to basic resuscitative efforts.

Two

    paediatric
    AGE

 cases are reported in which

    unexpected, life-threatening arrhythmias
    SYMPTOMS

 occurred.

    Routine induction of general anaesthesia with thiopentone, 5 mg.kg-1,
    MEDICATION

 in one and

    with halothane
    MEDICATION

 in the other, and

    succinylcholine 1.25-1.5 mg.kg-1 i.v.
    MEDICATION

 was followed by the development of

    wide complex tachyarrhythmia
    SYMPTOMS

 with

    hypotension
    SYMPTOMS

 in the first case and

    asystole
    SYMPTOMS

 in the second case

    despite pre-treatment with atropine
    NEG_FINDINGS

 in both cases. The first patient was

    resuscitated with tracheal intubation, 100% oxygen, manual ventilation
    MEDICATION

 and

    intravenous lidocaine and bicarbonate
    MEDICATION

. The second patient required

    intubation, manual ventilation, 12 min of CPR and i.v. calcium, epinephrine and bicarbonate, as well as DC counter shock
    MEDICATION

. Neither patient

    received dantrolene
    NEG_FINDINGS

. Early recovery in both patients was

    uneventful
    SYMPTOMS

 with

    no neurological sequelae
    NEG_FINDINGS

. Subsequent investigations revealed the presence of a

    dystrophin-deficient muscular dystrophy
    DIAGNOSIS

,

    Duchenne muscular dystrophy
    DIAGNOSIS

 and

    Becker muscular dystrophy
    DIAGNOSIS

 respectively,

    previously unsuspected
    NEG_FINDINGS

, in both patients. The aetiology of the observed

    arrhythmias
    SYMPTOMS

 was presumably

    hyperkalaemia
    BIOCHEMICAL

, secondary to

    succinylcholine-induced rhabdomyolysis
    DIAGNOSIS

. It is suggested that when faced with

    sudden, life-threatening arrhythmias
    SYMPTOMS

 following

    succinylcholine at induction of anaesthesia
    MEDICATION

 for

    paediatric
    AGE

 patients, clinicians should include

    occult myopathy
    DIAGNOSIS

 in the

    differential diagnosis
    PARACLINICAL

, and thus consider the

    aggressive management of hyperkalaemia
    MEDICATION

 in addition to

    basic resuscitative efforts
    MEDICATION

.

despite pre-treatment with atropine
received dantrolene
no neurological sequelae
previously unsuspected

dystrophin-deficient muscular dystrophy
Duchenne muscular dystrophy
Becker muscular dystrophy
succinylcholine-induced rhabdomyolysis
occult myopathy


Chronic respiratory failure in limb-girdle muscular dystrophy: successful long-term therapy with nasal bilevel positive airway pressure.

Chronic respiratory failure is a major factor contributing to mortality in progressive neuromuscular disorders. Among the muscular dystrophies, respiratory failure most commonly occurs with Duchenne dystrophy, while in Becker, limb-girdle, and facioscapulo-humeral dystrophies, respiratory failure is infrequent and generally occurs in the more severe cases that have progressed to a nonambulatory, advanced functional stage. We report two brothers with a myopathic disease in which the distribution of weakness, initial clinical course, heredity, and muscle pathology most closely resembled a limb-girdle type of dystrophy. Both brothers, however, presented with chronic alveolar hypoventilation and respiratory failure when their locomotor disabilities were still mild. Respiratory failure was reversed, and satisfactory ventilation has been maintained for more than a year using a type of non-invasive intermittent positive pressure ventilation, with a bilevel positive airway pressure device (Bi-PAP), administered through a nasal mask during sleeping hours. These cases demonstrate an unusual presentation of limb-girdle dystrophy, and document that nocturnal, nasal administration of continuous airway pressure using the Bi-PAP device may be sufficient to maintain adequate long-term ventilation in some patients with neuromuscular causes of respiratory failure, and thus significantly improve quality of life and delay the need for more complex or invasive forms of assisted ventilation.

    Chronic respiratory failure
    SYMPTOMS

 is a major factor contributing to mortality in

    progressive neuromuscular disorders
    DIAGNOSIS

. Among the

    muscular dystrophies
    DIAGNOSIS

,

    respiratory failure
    SYMPTOMS

 most commonly occurs with

    Duchenne dystrophy
    DIAGNOSIS

, while in

    Becker
    DIAGNOSIS

,

    limb-girdle
    DIAGNOSIS

, and

    facioscapulo-humeral dystrophies
    DIAGNOSIS

,

    respiratory failure
    SYMPTOMS

 is infrequent and generally occurs in the more severe cases that have progressed to a

    nonambulatory, advanced functional stage
    SYMPTOMS

. We report two

    brothers
    GENDER

 with a

    myopathic disease
    DIAGNOSIS

 in which the

    distribution of weakness
    SYMPTOMS

, initial clinical course,

    heredity
    FAMILY

, and

    muscle pathology
    SYMPTOMS

 most closely resembled a

    limb-girdle type of dystrophy
    DIAGNOSIS

. Both

    brothers
    GENDER

, however, presented with

    chronic alveolar hypoventilation
    SYMPTOMS

 and

    respiratory failure
    SYMPTOMS

 when their

    locomotor disabilities were still mild
    NEG_FINDINGS

.

    Respiratory failure
    SYMPTOMS

 was reversed, and

    satisfactory ventilation has been maintained for more than a year using a type of non-invasive intermittent positive pressure ventilation, with a bilevel positive airway pressure device (Bi-PAP), administered through a nasal mask during sleeping hours
    MEDICATION

. These cases demonstrate an unusual presentation of

    limb-girdle dystrophy
    DIAGNOSIS

, and document that

    nocturnal, nasal administration of continuous airway pressure using the Bi-PAP device
    MEDICATION

 may be sufficient to

    maintain adequate long-term ventilation
    MEDICATION

 in some patients with

    neuromuscular causes
    DIAGNOSIS

 of

    respiratory failure
    SYMPTOMS

, and thus significantly improve quality of life and delay the need for more complex or

    invasive forms of assisted ventilation
    MEDICATION

.

progressive neuromuscular disorders
muscular dystrophies
Duchenne dystrophy
Becker
limb-girdle
facioscapulo-humeral dystrophies
myopathic disease
limb-girdle type of dystrophy
limb-girdle dystrophy
neuromuscular causes


Gene deletion causing adrenal hypoplasia congenita and hypogonadotrophic hypogonadism.

We report a patient with X-linked adrenal hypoplasia congenita and hypogonadotrophic hypogonadism in whom there were no clinical or biochemical features of either glycerol kinase deficiency or Duchenne muscular dystrophy. (The adrenal hypoplasia congenita and glycerol kinase loci map in Xp21 distal to Duchenne muscular dystrophy, and proximal to DXS727). DNA isolated from our patient was analysed by PCR amplification with primers for appropriate loci in the Xp21 region. This analysis revealed the absence of DXS319, which lies near the adrenal hypoplasia congenita deletion critical region, and the presence of DXS727, which is distal to the gene. The absence of glycerol kinase deficiency biochemically and clinically was consistent with the presence of one glycerol kinase exon product from PCR primers P17/P18 which lies within the glycerol kinase gene. The hypogonadotrophic hypogonadism is universally found in X-linked adrenal hypoplasia congenita and is thought to be pituitary in origin. These findings suggest that a gene locus resulting in hypogonadotrophic hypogonadism is present in the Xp21 region and is an integral part of the adrenal hypoplasia congenita gene or in close relationship to it.

We report a patient with

    X-linked
    GENETICS

    adrenal hypoplasia congenita
    DIAGNOSIS

 and

    hypogonadotrophic hypogonadism
    SYMPTOMS

 in whom there were

    no clinical or biochemical features of either glycerol kinase deficiency or Duchenne muscular dystrophy
    NEG_FINDINGS

. (The

    adrenal hypoplasia congenita and glycerol kinase loci map in Xp21 distal to Duchenne muscular dystrophy, and proximal to DXS727)
    DIAGNOSIS

.

    DNA isolated
    PARACLINICAL

 from our patient was

    analysed by PCR amplification with primers for appropriate loci in the Xp21 region
    PARACLINICAL

. This analysis revealed the

    absence of DXS319, which lies near the adrenal hypoplasia congenita deletion critical region, and the presence of DXS727, which is distal to the gene
    GENETICS

. The

    absence of glycerol kinase deficiency
    NEG_FINDINGS

 biochemically and clinically was consistent with the presence of

    one glycerol kinase exon product from PCR primers P17/P18 which lies within the glycerol kinase gene
    GENETICS

. The

    hypogonadotrophic hypogonadism
    SYMPTOMS

 is universally found in

    X-linked
    GENETICS

    adrenal hypoplasia congenita
    DIAGNOSIS

 and is thought to be

    pituitary
    SYMPTOMS

 in origin. These findings suggest that a

    gene locus resulting in hypogonadotrophic hypogonadism
    GENETICS

    is present in the Xp21 region and is an integral part of the adrenal hypoplasia congenita gene or in
    GENETICS

 close relationship to it.

hypogonadotrophic hypogonadism
hypogonadotrophic hypogonadism
pituitary


Dystrophin-related protein in Becker muscular dystrophy.

A benign Becker muscular dystrophy (BMD) patient with a marked decrease in dystrophin exhibited remarkable expression of dystrophin-related protein (DRP) on most of the muscle cell membrane. A phenotypic Duchenne muscular dystrophy patient with a truncated form of dystrophin exhibited no DRP expression on the muscle cell membrane except for the neuromuscular junction. Increased DRP expression might compensate for a lack of dystrophin in some BMD patients.

A

    benign Becker muscular dystrophy (BMD)
    DIAGNOSIS

 patient with a

    marked decrease in dystrophin
    BIOCHEMICAL

 exhibited

    remarkable expression of dystrophin-related protein (DRP) on most of the muscle cell membrane
    MICROSCOPIC

. A

    phenotypic Duchenne muscular dystrophy
    DIAGNOSIS

 patient with a

    truncated form of dystrophin
    GENETICS

 exhibited

    no DRP expression on the muscle cell membrane except for the neuromuscular junction
    MICROSCOPIC

.

    Increased DRP expression
    GENETICS

 might compensate for a

    lack of dystrophin
    BIOCHEMICAL

 in some

    BMD
    DIAGNOSIS

 patients.

benign Becker muscular dystrophy (BMD)
phenotypic Duchenne muscular dystrophy
BMD

marked decrease in dystrophin
lack of dystrophin

truncated form of dystrophin
Increased DRP expression


Assessment of the 50-kDa dystrophin-associated glycoprotein in Brazilian patients with severe childhood autosomal recessive muscular dystrophy.

Recently, we have demonstrated the specific deficiency of the 50-kDa dystrophin-associated glycoprotein (50DAG) in severe childhood autosomal recessive muscular dystrophy with Duchenne-like phenotype (SCARMD or AR-DLMD), a disease first reported in Tunisia and now presumed to be prevalent in North Africa and the Middle East. Here we demonstrate the deficiency of the 50DAG in one caucasoid and 5 negroid Brazilian patients with severe muscular dystrophy, which confirms that AR-DLMD with the 50DAG deficiency is not confined to the Arab populations. Without the analysis of both dystrophin and 50DAG, isolated male patients with this condition could be undiagnosed or misdiagnosed as having Duchenne or severe Becker muscular dystrophy. We also report, for the first time, the normal expression of the 50DAG and other dystrophin-associated proteins in one negroid and 2 caucasoid Brazilian patients with a phenotype indistinguishable from that of AR-DLMD with 50DAG deficiency. This is consistent with the genetic heterogeneity for the phenotype of AR-DLMD.

Recently, we have demonstrated the specific

    deficiency of the 50-kDa dystrophin-associated glycoprotein (50DAG)
    BIOCHEMICAL

 in

    severe childhood autosomal recessive muscular dystrophy with Duchenne-like phenotype (SCARMD or AR-DLMD)
    DIAGNOSIS

, a disease first reported in

    Tunisia
    ETHNICITY

 and now presumed to be prevalent in

    North Africa
    ETHNICITY

 and the

    Middle East
    ETHNICITY

. Here we demonstrate the

    deficiency of the 50DAG
    BIOCHEMICAL

 in one

    caucasoid
    ETHNICITY

 and 5

    negroid Brazilian
    ETHNICITY

 patients with

    severe muscular dystrophy
    DIAGNOSIS

, which confirms that

    AR-DLMD
    DIAGNOSIS

 with the

    50DAG deficiency
    BIOCHEMICAL

 is not confined to the

    Arab
    ETHNICITY

 populations. Without the

    analysis of both dystrophin and 50DAG
    PARACLINICAL

, isolated

    male
    GENDER

 patients with this condition could be

    undiagnosed or misdiagnosed as having Duchenne or severe Becker muscular dystrophy
    NEG_FINDINGS

. We also report, for the first time, the

    normal expression of the 50DAG and other dystrophin-associated proteins
    NEG_FINDINGS

 in one

    negroid
    ETHNICITY

 and 2

    caucasoid Brazilian
    ETHNICITY

 patients with a

    phenotype indistinguishable from that of AR-DLMD
    SYMPTOMS

 with

    50DAG deficiency
    BIOCHEMICAL

. This is consistent with the

    genetic heterogeneity
    GENETICS

 for the phenotype of

    AR-DLMD
    DIAGNOSIS

.

Tunisia
North Africa
Middle East
caucasoid
negroid Brazilian
Arab
negroid
caucasoid Brazilian


Atypical case of Becker's muscular dystrophy. Early identification and management.

A case of a child with Becker's muscular dystrophy is presented. Because of the genetic and clinical similarity with the more common Duchenne muscular dystrophy, these two diseases are compared. Since muscular dystrophy often initially presents with toe walking, flat-foot, and waddling gait, podiatrists may be the first physicians to see the child and provide early diagnosis.

A case of a

    child
    AGE

 with

    Becker's muscular dystrophy
    DIAGNOSIS

 is presented. Because of the genetic and clinical similarity with the more common

    Duchenne muscular dystrophy
    DIAGNOSIS

, these two diseases are compared. Since

    muscular dystrophy
    DIAGNOSIS

 often initially presents with

    toe walking
    SYMPTOMS

,

    flat-foot
    SYMPTOMS

, and

    waddling gait
    SYMPTOMS

,

    podiatrists
    PARACLINICAL

 may be the first physicians to see the

    child
    AGE

 and provide early diagnosis.

Becker's muscular dystrophy
Duchenne muscular dystrophy
muscular dystrophy


Prenatal exclusion of Duchenne muscular dystrophy by fetal muscle biopsy.

A fetal thigh muscle biopsy was performed at 18 weeks and 6 days' gestation using an automatic 18-gauge biopsy needle. A positive immunoreaction with antisera to the amino- and carboxy-terminals of dystrophin excluded Duchenne muscular dystrophy from this at-risk male.

A

    fetal thigh muscle biopsy
    PARACLINICAL

 was performed

    at 18 weeks and 6 days' gestation
    AGE

 using an

    automatic 18-gauge biopsy needle
    PARACLINICAL

. A

    positive immunoreaction with antisera to the amino- and carboxy-terminals of dystrophin
    BIOCHEMICAL

 excluded

    Duchenne muscular dystrophy
    DIAGNOSIS

 from this at-risk

    male
    GENDER

.


Occurrence of two different intragenic deletions in two male relatives affected with Duchenne muscular dystrophy.

The occurrence of 2 different intragenic deletions (exons 10-44 and exon 45, respectively) is reported in 2 male relatives affected with Duchenne muscular dystrophy, both showing the same haplotype for DNA markers not included in the deleted segment. The 2 different deletions seem to have occurred independently in the same X chromosome. This finding, together with other reports, suggests possibly an increased predisposition to mutations within the DMD locus in some families. Therefore, when dealing with prenatal diagnosis, the investigation on fetal DNA cannot be restricted only to the region in which a mutation was previously identified in the family.

The

    occurrence of 2 different intragenic deletions (exons 10-44 and exon 45, respectively)
    GENETICS

 is reported in 2

    male
    GENDER

    relatives affected with Duchenne muscular dystrophy
    FAMILY

,

    both showing the same haplotype for DNA markers not included in the deleted segment
    FAMILY

.

    The 2 different deletions seem to have occurred independently in the same X chromosome
    GENETICS

. This finding, together with other reports, suggests possibly an

    increased predisposition to mutations within the DMD locus
    GENETICS

 in some families. Therefore, when dealing with

    prenatal diagnosis
    PARACLINICAL

, the

    investigation on fetal DNA
    PARACLINICAL

 cannot be restricted only to the region in which a

    mutation was previously identified in the family
    FAMILY

.