Myotonic dystrophy affects more than 1 in 8,000 people worldwide.[1] While myotonic dystrophy can occur at any age, onset is typically in the 20s and 30s.[1] It is the most common form of muscular dystrophy that begins in adulthood.[1] It was first described in 1909, with the underlying cause of type 1 determined in 1992.[2]