Early myocardial disease and cramping myalgia in Becker-type muscular dystrophy: a kindred.

We present a clinical and morphological study concerning a kindred with slowly progressive X-linked muscular dystrophy (Becker type). Five males were affected; one died of heart failure at age 16. Severe and early cardiac disorder is unusual in this type of muscular dystrophy, and death at such an early age had not been reported previously. In the other patients of the kindred, cardiac abnormalities, if present at all, were nonspecific. Another unusual feature in this kindred was severe muscle pain at an early stage of the disease, a feature that cannot yet be explained.