Familial syndrome of mental retardation, short stature, contractures of the hands, and genital anomalies.

Two teen-age XY brothers with mental retardation, short stature, obesity, genital abnormalities, and contractures of their hands are described. They have generalized osteoporosis and a history of frequent fractures. Their endocrinologic evaluation was normal except for mild glucose intolerance and delayed, but normal puberty. Although these brothers are similar to individuals with Prader-Willi syndrome, their unusual hand contractures, clinically significant osteoporosis, and lack of hypotonia indicate that they represent a different entity.