For example, mutations in α-galactosidase A (GLA, Fabry Disease), β-hexosaminidase (HEXA/HEXB, GM2 gangliosidosis) or NPC1 (Niemann-Pick Disease type C1) will cause primary storage of globotriaosylceramide, GM2 ganglioside, or cholesterol, respectively1. The gene discussed is HEXA; the disease is Niemann-Pick disease type C.