Hypertrophic cardiomyopathy (HCM) in infancy has been described in associat
ion with many medical disorders. The genetic location and mode of transmiss
ion of HCM in families also has been reported extensively. We present an in
fant with nonobstructive hypertrophic cardiomyopathy whose mother also had
HCM. Regression of septal hypertrophy was documented in this patient by 1 y
ear of age despite a positive family history.