Hypertrophic cardiomyopathy in late‐onset variant of Fabry disease with high residual activity of α‐galactosidase A

A new variant form of Fabry disease with hypertrophic cardiomyopathy of late onset is reported. Two unrelated male hemizygotes of this disease first presented with signs and symptoms of cardiomyopathy after 50 years of age. Cultured lymphoblastoid cells showed significantly higher residual alpha-galactosidase A activities than in the patients with classical phenotypic expressions.