An Atypical Cardiac Manifestation of Fabry Disease from a Novel Pathological Variant on the GLA Gene

Fabry disease (FD) is one of the most common lysosomal storage disorders and is caused by an X-linked progressive inborn error of metabolism in the alpha-galactosidase A (α-Gal A) gene. This leads to intracellular accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb3), throughout the body. The impact of this accumulation is seen across multiple cell lines and therefore can cause multisystem organ dysfunction. The phenotype of FD results from variants on the GLA gene which codes for α-Gal A production, and variants on this gene have been shown to be strongly related to unexplained or idiopathic cardiovascular disorders. This report describes a 36-year-old Caucasian male found to have left ventricular hypertrophy (LVH) followed by genetic testing because of his family history of sudden cardiac death which revealed a variant of unknown significance for the GLA gene. Further measurement of α-Gal A leukocyte activity showed low levels, which was diagnostic for FD. The index patient had an unusual non-classic phenotype in that his sole presenting symptom was asymptomatic LVH, he presented early, and had low α-Gal A leukocyte activity. Early detection and prompt treatment with enzyme replacement therapy can improve outcomes and decrease mortality. In the absence of known risk factors, non-classical FD should be strongly considered in patients with unexplained LVH and a family history of sudden cardiac death at a young age.