85% of MGN cases are classified as primary membranous glomerulonephritis—that is to say, the cause of the disease is idiopathic (of unknown origin or cause).
MGN85％的病例被分類為原發性膜性腎小球腎炎(primary membranous glomerulonephritis)，即疾病的病因是特發性(Idiopathy)(原因或起病源待查)。