GBA1 and lysosomal storage disease: Gaucher disease (GD) (OMIM 23080, 231000, 231005), the most common lysosomal storage disorder (LSD), is caused by pathologic GBA variants (OMIM 606463), resulting in the deficiency of the lysosomal membrane enzyme glucocerebrosidase (GCase) (EC 3.2.1.45).