Myotonic dystrophy type 1 (DM1) is the most common cause of adult-onset muscular dystrophy, a genetic disorder that leads to muscle weakness and wasting, but also affects the brain, the gastrointestinal tract and the heart.

Myotonic dystrophy type 1 (DM1) is the most common cause of adult-onset muscular dystrophy, a genetic disorder that leads to muscle weakness and wasting, but also affects the brain, the gastrointestinal tract and the heart.