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Myotonic dystrophy: Etiology, clinical features, and diagnosis

Basil T Darras, MD
David A Chad, MD
Section Editors
Jeremy M Shefner, MD, PhD
Douglas R Nordli, Jr, MD
Deputy Editor
John F Dashe, MD, PhD


Myotonic dystrophy (DM) is a clinically and genetically heterogeneous disorder. There are two major forms:

DM1, for a century known as Steinert disease

DM2, recognized in 1994 as a milder version of DM1

These autosomal dominant conditions are among the most common forms of adult-onset muscular dystrophy. However, DM is more than simply a muscular dystrophy per se, since affected individuals may show cataracts, cardiac conduction abnormalities, infertility, and insulin resistance. Furthermore, there is a severe congenital form of DM1 with marked developmental disability.

One consequence of the multisystemic nature of this disorder is that individuals affected by DM1 or DM2 may first present to internists, cardiologists, ophthalmologists, endocrinologists, and pediatricians (in the case of DM1), before they see a neurologist.


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Literature review current through: Nov 2016. | This topic last updated: Mon Nov 28 00:00:00 GMT 2016.
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