NPC has an autosomal recessive inheritance pattern, with most causative mutations (95%) located in the NPC1 gene (NPC1 disease, OMIM: 257220), and the remainder (5%) located in the NPC2 gene (NPC2 disease, OMIM: 607625) (Loftus et al., 1997; Naureckiene et al., 2000; Vanier and Millat, 2003). The gene discussed is NPC2; the disease is nasopharyngeal carcinoma.