What is "myotonic dystrophy"

n. a severe form of muscular dystrophy marked by generalized weakness and muscular wasting that affects the face and feet and hands and neck; difficult speech and difficulty with the hands that spreads to the arms and shoulders and legs and hips; the onset can be any time from birth to middle age and the progression is slow; inheritance is autosomal dominant [syn: myotonic muscular dystrophy, myotonia atrophica, Steinert's disease]

Myotonic dystrophy (dystrophia myotonica, myotonia atrophica) is a chronic, slowly progressing, highly variable, inherited multisystemic disease. It is an autosomal-dominant disease. It is characterized by wasting of the muscles ( muscular dystrophy), cataracts, heart conduction defects, endocrine changes, and myotonia.

There are two main types of myotonic dystrophy. Myotonic dystrophy type 1 (DM1), also called Steinert disease, has a severe congenital form and an adult-onset form. Myotonic dystrophy type 2 (DM2), also called proximal myotonic myopathy (PROMM) is rarer than DM1 and generally manifests with milder signs and symptoms. Myotonic dystrophy can occur in people of any age. Both forms of the disease display an autosomal-dominant pattern of inheritance. Both "DM1" and "DM2" have adult-onset forms.