OBJECTIVETo investigate the clinical characteristics and gene mutations of patients with Gilbert syndrome complicated with myeloproliferative neoplasms (MPN).

METHODSPeripheral blood samples from 1 patient with Gilbert syndrome complicated with MPN and his son were collected to analyse all exon mutations of UGT1A1 gene.

RESULTSThe patient with leukocytosis, thrombocythemia, mild anemia and positive JAK2/V617F mutation was initially diagnosed as MPN. The hyperbilirubinemia suggested concurrent disease. Further gene evaluation disclosed a insertion mutation in the (TA)TAA box, and a missense mutation(G→A) at 211 bp of exon 1, corresponding to the deficiency in the bilirubin-conjugating enzyme uridine-diphosphoglucuronosyl transferase1A1 (UGT1A1). His son only carried some polymorphism mutation without manifestation of this disease.

CONCLUSIONIt is a first report case of MPN complicated with Gilbert syndrome that can highlight the differential diagnosis for hyperbilirubinemia.