Genotype–Phenotype Association in ABCC2 Exon 18 Missense Mutation Leading to Dubin–Johnson Syndrome: A Case Report

We report a case of a patient with Dubin–Johnson syndrome confirmed by a genetic study. A 50-year-old woman who had symptoms of intermittent right upper quadrant abdominal pain was diagnosed with calculous cholecystitis at another institute and was presented to our hospital for a cholecystectomy. She had no history of liver disease, and her physical examination was normal. Abdominal computed tomography showed a gallbladder stone with chronic cholecystitis. During a laparoscopic cholecystectomy for cholecystitis, a smooth, black-colored liver was noted, and a liver biopsy was performed. The biopsy specimen showed coarse, dark brown granules in centrilobular hepatocytes via hematoxylin and eosin staining. We performed a genetic study using the blood samples of the patient. In the adenosine triphosphate-binding cassette subfamily C member 2 (ABCC2) mutation study, a missense mutation in exon 18 was noted. Based on the black-colored liver without nodularity, conjugated hyperbilirubinemia, the liver biopsy results of the coarse pigment in centrilobular hepatocytes, and the ABCC2 mutation, Dubin–Johnson syndrome was diagnosed. The patient was managed with conservative care using hepatotonics. One month after follow-up, total bilirubin and direct bilirubin remained in a similar range. Another follow-up was planned a month later, and the patient maintained her use of hepatotonics.