MedGen

Nasopharyngeal carcinoma (NPC, NPCA) is a multifactorial malignancy associated with both genetic and environmental factors. The cancer arises from the epithelium of the nasopharynx. The Epstein-Barr virus has been implicated (Tse et al., 2009). Genetic Heterogeneity of Susceptibility to Nasopharyngeal Carcinoma NPCA1 maps to chromosome 4p. NPCA2 (161550) maps to chromosome 6p21. NPCA3 (617075) is associated with variation in the MST1R gene (600168) on chromosome 3p21. Somatic mutations have been found in the TP53 gene (191170) in nasopharyngeal carcinoma tumors. [from OMIM]

Niemann-Pick disease type C (NPC) is a slowly progressive lysosomal disorder whose principal manifestations are age dependent. The manifestations in the perinatal period and infancy are predominantly visceral, with hepatosplenomegaly, jaundice, and (in some instances) pulmonary infiltrates. From late infancy onward, the presentation is dominated by neurologic manifestations. The youngest children may present with hypotonia and developmental delay, with the subsequent emergence of ataxia, dysarthria, dysphagia, and, in some individuals, epileptic seizures, dystonia, and gelastic cataplexy. Although cognitive impairment may be subtle at first, it eventually becomes apparent that affected individuals have a progressive dementia. Older teenagers and young adults may present predominantly with apparent early-onset dementia or psychiatric manifestations; however, careful examination usually identifies typical neurologic signs. [from GeneReviews]