• Fabry disease
• hypertrophic cardiomyopathy

The evaluation of hypertrophic cardiomyopathy (HCM) involves the careful consideration of diseases that can mimic its appearance, such as aortic stenosis, poorly controlled hypertension, and infiltrative processes such as cardiac amyloidosis. Fabry disease, an inherited deficiency of the enzyme α galactosidase A, in particular, has recently received much attention for new and nearly curative treatments.^1,2 Exogenous administration of the deficient enzyme has been shown to clear microvascular endothelial deposits, which are integral to disease manifestation, in the kidney, skin, and heart. Interestingly, isolated cardiac Fabry disease may exist without other overt manifestations. In one study, 3% of male subjects with myocardial hypertrophy were found to harbour this enzyme deficiency,³ whereas another study showed that approximately 4% of patients referred to a tertiary centre for evaluation of HCM actually had evidence of Fabry disease.⁴ If this storage disease were misdiagnosed as HCM, patients who could be treated effectively with medication might be subjected to …