Approximately 95% of Niemann–Pick<unk>  C cases are caused by genetic mutations in the NPC1 gene, referred to as<unk>  C1; 5% are caused by mutations in the NPC2 gene, referred to as<unk>  C2. The clinical manifestations of<unk> s Niemann–Pick<unk> s C1 and C2 are similar because the respective genes are both involved in egress of lipids, particularly cholesterol, from late endosomes or lysosomes. The NPC1 gene is located on chromosome 18 (18q11-q12) and was described by researchers at the National Institutes of Health in July 1997. * The NPC1 gene encodes a protein that is located in membranes inside the cell and is involved in the movement of cholesterol and lipids within cells. A deficiency of this protein leads to the abnormal buildup of lipids and cholesterol within cell membranes. * The NPC2 gene encodes a protein that binds and transports cholesterol. It has been shown to closely interact with NPC1. "Type D" variant<unk>  D Niemann–Pick has only been found in the French Canadian population of Yarmouth County, Nova Scotia, and is now known to be allelic with Niemann–Pick<unk>  C. Genealogical research indicates that Joseph Muise (c. 1679–1729) and Marie Amirault (1684<unk>  c. 1735) are common ancestors to all people with<unk>  D. This couple is the most likely origin for the<unk>  D variant.
Niemann–Pick disease, type C
Niemann–Pick disease, SMPD1-associated
Wilson–Mikity syndrome
Haemochromatosis type 3
Hemochromatosis type 4
Wilson's disease
Mowat–Wilson syndrome
Bannayan–Riley–Ruvalcaba syndrome