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Incidence of Niemann-Pick type C disease

There is very little epidemiologic data on Niemann-Pick type C (NP-C), mainly due to lack of specific laboratory testing until the 1980s and the wide clinical spectrum of the disease, which went largely unrecognized until the early 1990s.1

The minimal incidence of NP-C was initially estimated to be one in every 120,000 live births, based on diagnoses over a 14-year period.1 However, this was considered to be an underestimation due to its heterogeneous clinical presentation, lack of clinical awareness of the disease and the difficulties with biochemical testing.1 More recent analysis of four large, independent exome sequencing databases suggests that NP-C may be more prevalent than previously determined, with incidence rates of 1/92,104 and 1/2,858,998 for NP-C1 and NP-C2, respectively, and a combined incidence of 1/89,229 for classical NP-C.2 Findings from the same study also suggest that, when accounting for common NPC1 variants, there may be a late-onset NP-C1 phenotype with a markedly higher incidence of 1/19,000–1/36,000.2

NP-C generally arises sporadically in a panethnic pattern, although genetic isolates have been identified that show a higher than average incidence of the disease.3


  1. Vanier MT. Niemann-Pick disease type C. Orphanet J Rare Dis 2010;5:16.
  2. Wassif CA, Cross JL, Iben J, et al. High incidence of unrecognized visceral/neurological late-onset Niemann-Pick disease, type C1, predicted by analysis of massively parallel sequencing data sets. Genet Med. 2016;18:41–8. 
  3. Patterson MC, Hendriksz CJ, Walterfang M, et al., on behalf of the NP-C Guidelines Working Group. Recommendations for the diagnosis and management of Niemann–Pick disease type C: An update Mol Genet Metab 2012;106:330–44.