Familial neurofibromatosis and hypertrophic cardiomyopathy.

Two siblings from a family in which neurofibromatosis was inherited as an autosomal dominant had hypertrophic cardiomyopathy and neurofibromatosis. Idiopathic hypertrophic cardiomyopathy may have occurred by chance in two first degree relatives with neurofibromatosis. An alternative explantation is that these diseases are both manifestations of a common hereditary defect of neural crest tissue. Another possibility is that abnormalities of catecholamine metabolism and nerve growth factor in neurofibromatosis can cause secondary ventricular hypertrophy with septal involvement.