myotonic dystrophy
Myotonic dystrophy (DM), the most common form of muscular dystrophy in adults, is a clinically and genetically heterogeneous neuromuscular disorder. DM is characterized by autosomal dominant inheritance, muscular dystrophy, myotonia, and multisystem involvement.
Etiology
Type 1 DM (DM1) is caused by a (CTG)(n) expansion in the 3’ untranslated region of the DMPK gene in 19q13.3.
Type 2 DM (DM2) but without the DM1 mutation, showed linkage to the 3q21 region and were recently shown to segregate a (CCTG)(n) expansion mutation in intron 1 of ZNF9.
Type 3 DM (DM3) 3q21
References
Harris S, Moncrieff C, Johnson K. Myotonic dystrophy: will the real gene please step forward! Hum Mol Genet. 1996;5 Spec No:1417-23. PMID: #8875246#
Ozawa E, Yoshida M, Suzuki A, Mizuno Y, Hagiwara Y, Noguchi S. Dystrophin-associated proteins in muscular dystrophy. Hum Mol Genet. 1995;4 Spec No:1711-6. PMID: #8541869#