The study’s goal was to look into the relevance of sodium taurocholate cotransporting polypeptide (NTCP) deficit and its clinical manifestations in Chinese infants with isolated chronic hypercholanemia. In 33 Chinese infants with isolated hypercholanemia, the exon and surrounding areas of SLC10A1, the gene encoding NTCP, were sequenced. The clinical history and medical records were examined. Growth indicators were compared to the national average. The serum direct bilirubin concentration was compared to age- and sex-matched controls at the final follow-up. All participants had an SLC10A1 mutation, c.800C>T, p. S267F; 30 were homozygotes and 3 were compound heterozygotes. Nine individuals had transitory newborn cholestasis, and one had chronic moderate conjugated hyperbilirubinemia. Even beyond the neonatal cholestasis stage, the blood direct bilirubin level in NTCP-deficient patients was substantially greater than in age- and sex-matched controls. There was no evidence of growth retardation or any serious long-term clinical effects.
In Han Chinese children, NTCP deficiency is the sole or primary cause of isolated hypercholanemia, with c.800C>T being the major contributing genetic variant. The abnormality may impact bilirubin metabolism and manifest as transitory newborn cholestasis and/or chronic moderate conjugated hyperbilirubinemia, although no long-term clinical implications are observed.