GLA and Fabry disease: Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by GLA gene mutations, leading to deficient α-galactosidase A (α-Gal A) activity and progressive accumulation of globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3) in multiple tissues.