Niemann-Pick Disease is caused by mutations in specific genes responsible for lipid metabolism. For instance, Type A and Type B are caused by mutations in the SMPD1 gene, which encodes the enzyme acid sphingomyelinase. This enzyme is crucial for the breakdown of sphingomyelin, a type of lipid. In Type C, mutations occur in either the NPC1 or NPC2 genes, which are involved in the transport of cholesterol and other lipids within cells. The mutations lead to the defective processing and accumulation of these lipids.
