Definition Myotonic dystrophy (MD) is a muscular disorder characterized by prolonged contraction and delay of relaxation of muscles, progressive muscle weakness, and wasting. Incidence is 1 in 8000 Signs and symptoms of MD1 include muscle weakness and wasting (especially in the cranial and distal limb musculature), myopathy, periodic myotonia, cardiac conduction abnormalities, insulin resistance, neuropsychiatric impairment, and cataracts (as well as […]