A case of anorexia nervosa with hyperbilirubinaemia in a patient homozygous for a mutation in the bilirubin UDP-glucuronosyltransferase gene.

UNLABELLED: Gilbert syndrome was diagnosed in a girl with anorexia nervosa and unconjugated hyperbilirubinaemia. Since the patient was starved and hyperbilirubinaemic, the loading test was not used for the diagnosis but analysis of the bilirubin UDP-glucuronosyltransferase gene (UGT1A1) instead. The patient was homozygous for a missense mutation that replaced guanine with adenine at nucleotide number 211 (211G-->A: G71R). The unconjugated hyperbilirubinaemia was apparently induced by the fasting state. Homozygous missense mutations of the gene have been generally recognized as responsible for Crigler-Najjar syndrome type II; the results obtained here, however, confirm that Gilbert syndrome may also be caused by a homozygous missense mutation of UGT1A1.
CONCLUSION: Since anorexia nervosa patients are in a fasting state, they may show moderate unconjugated hyperbilirubinaemia if they have Gilbert syndrome. Gene analysis of such cases will rule out hepatic damage. Homozygous missense mutations of the bilirubin-UDP-glucuronosyltransferase gene cause not only Crigler-Najjar syndrome type II but also Gilbert syndrome.