The following particular search terms in different combinations with filters for case reports, clinical trials, and reviewed articles were used in order to find the most suitable papers for this review: “Niemann–Pick disease”, “acid-sphingomyelinase deficiency”, “genetic traits in NPD-A and NPD-B”, “enzyme replacement therapy”, “olipudase-alfa”, “metabolic disorder” or “sphingomyelin”. This evidence concerns the gene SMPD1 and hyperinsulinemic hypoglycemia, familial, 4.