Myotonic dystrophy

[Tracie Lynn]

Myotonic dystrophy is a rare muscular dystrophy. This disorder affects the ability to relax the muscles at will.

Myotonia refers to delayed relaxation after muscle contraction, which can cause muscle stiffness. Muscular dystrophies are a group of inherited muscle disorders in which one or more genes needed for normal muscle structure and function are defective, leading to muscle weakness and muscle wasting (dystrophy) of varying severity.

Myotonic dystrophy is an autosomal dominant disorder, which means only one affected parent is needed to pass the trait on to offspring. This dystrophy affects males and females and about 1 in 8,000 people.