Niemann–Pick<unk>  C is diagnosed by assaying cultured fibroblasts for cholesterol esterification and staining for unesterified cholesterol with filipin. The fibroblasts are grown from a small skin biopsy taken from a patient with suspected NPC. The diagnosis can be confirmed by identifying mutations in the NPC1 or NPC2 genes in 80–90% of cases. This specialized testing is available at Thomas Jefferson University Lysosomal Disease Testing Lab and the Mayo Clinic.
Niemann–Pick disease, type C
Niemann–Pick disease, SMPD1-associated
Wilson–Mikity syndrome
Haemochromatosis type 3
Hemochromatosis type 4
Wilson's disease
Mowat–Wilson syndrome
Bannayan–Riley–Ruvalcaba syndrome