Causes

Mutations in the Sphingomyelin phosphodiesterase 1(SMPD1) gene cause Niemann- Pick disease types A and B. Mutations in the Niemann- Pick disease type C1 and C2 cause Niemann- Pick disease type C. NPC1 and NPC2 are proteins in the human body. This disease is inherited through an autosomal recessive pattern which means both copies. Both parents may have the disease but are not affected which mean that they are carriers. If both parents are carriers there is a 25% chance that the child may be affected.