Niemann Pick disease type C (NP-C) is a neurovisceral lysosomal storage disorder caused by autosomal recessive mutations in the NPC1 (≥95% of cases) or the NPC2 gene and is characterized by impaired trafficking of cholesterol and sphingolipids (reviewed in [1, 2]). The gene discussed is NPC1; the disease is Niemann-Pick disease type C.