S5827 A Case of Dubin-Johnson Syndrome Overlapping With Hepatic Steatosis

Introduction: Dubin-Johnson Syndrome (DJS) is a benign rare cause of persistent conjugated hyperbilirubinemia that occurs due to autosomal recessive mutations of the ATP binding cassette subfamily C member gene. Most patients are diagnosed during adolescence, solely presenting with mild scleral icterus. We present a case of DJS in a middle-aged patient with concurrent hepatic steatosis. To make the diagnosis, a high degree of suspicion and consideration of an inherited disorder in the differential despite the patient’s older age was required. Case Description/Methods: A 44-year-old man with Type 2 diabetes and dyslipidemia presented several months of gradual onset asymptomatic persistent jaundice. His medications consisted of rosuvastatin and metformin. The patient consumed 1-2 alcoholic drinks per week. Physical exam revealed a body mass index of 36.3 and scleral icterus but was otherwise unremarkable. HbA1c was 6.4%, lipid panel was normal, and alanine aminotransferase (ALT) was slightly elevated with conjugated hyperbilirubinemia. Twenty-four-hour urine porphyrins were elevated at 461 nmol/day, of which 439 nmol was urine coproporphyrin (90% coproporphyrin I). A transabdominal ultrasound showed severe fatty infiltration of the liver while transient elastography demonstrated normal liver stiffness. The patient was advised to increase his exercise and modify his diet, which resulted in normalization of his ALT level in 3 months. His sister was later diagnosed with DJS. Discussion: A high degree of suspicion is needed to diagnose DJS in an adult, especially in the presence of other confounding conditions such as metabolic dysfunction–associated steatotic liver disease or alcohol use. Clues suggesting DJS include asymptomatic scleral icterus, normal liver enzymes, and conjugated hyperbilirubinemia; an elevated urinary coproporphyrin I fraction is diagnostic and can distinguish DJS from Rotor Syndrome, which is another inherited hyperbilirubinemia.