Prevalence of Anderson-Fabry Disease in Male Patients With Late Onset Hypertrophic Cardiomyopathy

Abstract

Background — Although studies have suggested that “late-onset” hypertrophic cardiomyopathy (HCM) may be caused by sarcomeric protein gene mutations, the cause of HCM in the majority of patients is unknown. This study determined the prevalence of a potentially treatable cause of hypertrophy, Anderson-Fabry disease, in a HCM referral population. Methods and Results — Plasma α-galactosidase A (α-Gal) was measured in 79 men with HCM who were diagnosed at ≥40 years of age (52.9±7.7 years; range, 40–71 years) and in 74 men who were diagnosed at <40 years (25.9±9.2 years; range, 8–39 years). Five patients (6.3%) with late-onset disease and 1 patient (1.4%) diagnosed at <40 years had low α-Gal activity. Of these 6 patients, 3 had angina, 4 were in New York Heart Association class 2, 5 had palpitations, and 2 had a history of syncope. Hypertrophy was concentric in 5 patients and asymmetric in 1 patient. One patient had left ventricular outflow tract obstruction. All patients with low α-Gal activity had α-Gal gene mutations. Conclusion — Anderson-Fabry disease should be considered in all cases of unexplained hypertrophy. Its recognition is important given the advent of specific replacement enzyme therapy.