ABSTRACT
In Niemann-Pick type C disease, the trafficking of lipid within the cell leads to accumulation of unesterified cholesterol in lysosomes and late endosomes. Niemann-Pick type C is an autosomal recessive lysosomal storage disease. The diagnosis of Niemann-Pick type C disease is currently made in cultured fibroblasts by demonstration of both impaired cholesterol esterification and the positive filipin test for accumulation of free-cholesterol. An aid to diagnosis may be obtained by assay of the activity of chitotriosidase. This activity is significantly increased in Gaucher disease. It may be moderately elevated in Niemann-Pick type C disease and some other lysosomal storage diseases, but it may be normal too. Despite the large and increasing body of knowledge about the metabolism and transport of cholesterol and other lipids, the pathogenesis of the neurologic features of Niemann-Pick type C disease remains obscure. Supportive care including physical and occupational therapy is important.
