OBJECTIVETo explore the clinical and genetic characteristics of a family affected by genetic cholestasis.

METHODSClinical data of the patient was collected. Targeted exome sequencing was carried out to detect the pathogenic mutations. The results were confirmed by Sanger sequencing.

RESULTSThe patient, a 5-year-old boy, presented with severe cholestatic cirrhosis. Genetic analysis revealed that he has carried compound heterozygous mutations c.1006-2A>G and c.3580C>T (p.R1194X) of the ABCB4 gene, which were inherited from his father and mother, respectively. By structural prediction, the mutation c.3580C>T can give rise to a truncated multi-drug resistance protein 3 (MDR3).

CONCLUSIONThe patient was diagnosed with progressive familial intrahepatic cholestasis type 3 (PFIC-3) based on clinical and molecular findings. Detection of novel mutations of the ABCB4 gene has provided valuable clues for the diagnosis and genetic counseling.