Background of the antigen
NPC2 is a secreted protein mapping against gene 14q24.3 (1,2). NPC2 regulates the lipid composition of sperm membranes during maturation in the epididymis(1,2). Mutations in the NPC2 gene may cause Nieman-Pick type C2 disease and frontal lobe atrophy (1,2,3). Nieman-Pick type C2 is a fatal hereditary disease characterized by defective lysosome release of cholesterol (3). The disease is caused by HE1 deficiency, a lysosmal protein proven to be undetectable in fibroblasts from NPC2 patients (3). This differentiates NPC2 from NPC1, as NPC1 has HE1 protein present (3).
