Identification of two subtypes of infantile acid maltase deficiency

Infantile patients with acid maltase deficiency have severe hypertrophic ca rdiomyopathy, left ventricular outflow obstruction, and generalized muscle weakness and die before 1 year of age. We identified 12 infants with acid m altase deficiency who had a similar clinical presentation but less severe c ardiomyopathy and absence of left ventricular outflow obstruction, and 9 of 12 had longer survival with assisted ventilation and supplemental intubati on.