STUDIES IN DISEASES OF MUSCLE

Abstract

Progressive muscular dystrophy is generally regarded as a "hereditary disease" because patients with this condition frequently give a history of other members of the family who have been similarly affected. Numerous families have been reported in which the disease has appeared in different generations, but the genealogic studies thus far have been too few and incomplete. In consequence, the mechanism of the hereditary transmission of progressive muscular dystrophy is still imperfectly understood. The difficulties usually encountered in obtaining data on heredity in human beings are considerably increased in the case of progressive muscular dystrophy. Unlike conditions, such as hemophilia and color blindness, which can always be demonstrated early in life in affected persons and of which the mode of hereditary transmission is well understood, progressive muscular dystrophy need not manifest itself until later in life. Therefore, members of the family who are without symptoms cannot be considered free from the