A case of endomyocardial biopsy-proven early stage cardiac involvement in heterozygous Fabry disease

Fabry disease is a lysosomal disorder caused by a deficiency in α-galactosidase A. Heterozygous female patients remain free of serious complications, including cardiovascular symptoms, until late in life. This often makes it difficult to decide on the best time to initiate treatment in female patients. Still, it is important to initiate treatment before the disease progresses too far.We report the case of a 39-year-old asymptomatic female patient with Fabry disease [heterozygous p.Arg301Pro (c.902 G>C) variant in the 6th exon of α-galactosidase A (NM_000169.3)]. After 8 years of follow-up, increased QRS voltage and strain T waves developed in the left precordial electrocardiogram leads in the absence of hypertension, left ventricular hypertrophy or ischemia. Echocardiography, cardiac magnetic resonance, and coronary angiography showed normal findings. Through endomyocardial biopsy, the patient was ultimately diagnosed with early stage cardiac involvement of her Fabry disease, and chaperon therapy was initiated. Follow-up after one year revealed reduction of both the electrocardiogram abnormality and microalbuminuria, suggesting disease progression was halted.This case highlights importance of prompt diagnosis of asymptomatic Fabry disease through endomyocardial biopsy as well as the potential benefit of chaperon therapy.