Fabry cardiomyopathy in the female confirmed by endomyocardial biopsy.

A 58-year-old woman with cardiac enlargement and heart failure was a member of a family with Fabry disease. In this patient, endomyocardial biopsy permitted microscopic examination of the myocardium which revealed cellular abnormalities characteristic of Fabry cardiomyopathy. It is suggested that unfavorable lyonization of the mutant-bearing X chromosome accounted for the expression of this disorder in specific organs of a female patient.