There are a number of different types of muscular dystrophy. This fact sheet deals only with Myotonic Dystrophy. The Muscular Dystrophy Association deals with a wide variety of disorders which affect muscles, nerves which control muscles and the interactions between the two. Please contact the MDA for further information. Myotonic dystrophy is the most common adult form of muscular dystrophy.
Myotonic dystrophy is caused by a defective gene.
The disorder is also known as Steinert's disease and dystrophia myotonica. Delayed relaxation of voluntary muscles after contractions is often a problem even before muscle weakness is apparent. However, this is generally less noticeable after the early stages of myotonic symptom that is probably the most troublesome is the inability to release the hand from a grip. Myotonic dystrophy shows an early pattern of muscle wasting that is unique among the major muscular dystrophies. Myotonic dystrophy can affect the tissues and organs of many body systems in addition to the voluntary muscle system.