Myotonic dystrophy, type 2 is an inherited disorder of the muscles and other body systems. Type 2 myotonic dystrophy tends to be milder than type 1, and the two forms are caused by mutations in different genes. Myotonic dystrophy, type 2 is a subtype of myotonic dystrophy. Many of the signs and symptoms seen with this disorder are similar to those of type 1 myotonic dystrophy, including progressive muscle weakness, prolonged muscle contractions (myotonia), clouding of the lens of the eye (cataracts), cardiac abnormalities, balding, and infertility. The clinical features of type 2 vary widely among people, however, and tend to be milder than those seen with type 1 myotonic dystrophy. Congenital myotonic dystrophy (a form of the disorder that is evident from birth) has not been seen in families with type 2.