NPC2 and nasopharyngeal carcinoma: Typically, a diagnosis is confirmed by biochemical (filipin staining of skin fibroblasts) and genetic analysis (DNA sequencing of the NPC1 and NPC2 genes, the loci that confer 95 % and 5 % of NP-C cases, respectively) [7, 9]; however, rapid biochemical tests utilising biomarkers such as plasma oxysterols or lysosphingolipids are in development, and may improve rates of diagnosis [10–12].