CHIT1 and nasopharyngeal carcinoma: The guidelines also suggest that clinical and laboratory features that should raise a strong suspicion of NP-C include: (1) abnormal bone marrow aspirate that in some cases may demonstrate filipin-positive foam cells; (2) elevated plasma chitotriosidase activities (moderately raised in most cases); and (3) the presence of (hepato)splenomegaly with normal activities of acid sphingomyelinase (excluding Niemann Pick type A and B diseases) and β-glucocerebrosidase (excluding Gaucher disease).