Juvenile to adult onset myotonic dystrophy (Q101380)

Juvenile to adult onset myotonic dystrophy (DM) is an inherited muscular disorder. In the juvenile form symptoms appear between birth and adolescence, whereas in the adult form the onset is in individuals aged 20-40. Typical clinical manifestations include facial weakness, eyelids ptosis, muscle wasting in the forearms and calves, difficulty relaxing the grasp, and cardiac conduction defects. DM also causes constipation, cataracts, retinal degeneration, low IQ, early frontal balding, testicular atrophy, diabetes, and sleep apnoea. Severe disabilities do not usually set in until about 20 years after symptoms begin, and most patients maintain the ability to walk.