SLC10A1 and hyperinsulinemic hypoglycemia, familial, 4: Nevertheless, although NTCP deficiency has been predicted to result in hypercholanemia for years, previous reports of hypercholanemia-associated inherited disorders found causal mutations in genes other than SLC10A1, and these findings raised the possibility that an isolated NTCP gene defect may be asymptomatic, with limited impact on bile acid homeostasis [13].