The GLA gene maps to chromosome Xq22.1, where it encodes a lysosomal enzyme of 429 amino acids called alpha-galactosidase A. This enzyme hydrolyses the terminal alpha-galactosyl moieties from glycolipids and glycoproteins. It predominantly hydrolyzes ceramide trihexoside, and it can catalyze the hydrolysis of melibiose into galactose and glucose. Defects in this enzyme lead to the accumulation of globotriaosylceramide and related glycosphingolipids in the plasma and in the lysosomes of cells throughout the body, causing the signs and the symptoms of Fabry disease (FD), an X-linked sphingolipidosis disease characterized by stroke, acroparaesthesia, hypohidrosis, angiokeratoma, cornea verticillata, and cardiac and kidney disease.