Rotor syndrome

Rotor syndrome (also known as Rotor type hyperbilirubinemia) is a rare, benign hereditary condition characterized by predominantly conjugated (direct) hyperbilirubinemia. It was first described by Arturo Rotor and colleagues in 1948. The condition results from impaired hepatic storage and excretion of bilirubin conjugates, leading to their reflux back into the bloodstream. Rotor syndrome is caused by homozygous or compound heterozygous mutations in both the SLCO1B1 and SLCO1B3 genes, which encode organic anion-transporting polypeptides (OATP1B1 and OATP1B3) responsible for hepatic uptake of bilirubin and other substrates from the blood. The primary clinical feature is mild, chronic jaundice (yellowing of the skin and eyes) that typically presents during childhood or adolescence. Total serum bilirubin levels are usually elevated in the range of 2–5 mg/dL, with more than 50% being conjugated bilirubin. Unlike the related Dubin-Johnson syndrome, the liver in Rotor syndrome does not show dark pigmentation on biopsy, and coproporphyrin excretion in urine is markedly increased with a predominance of coproporphyrin I. Liver function tests are otherwise normal, and the liver histology appears normal. The condition is distinguished from Dubin-Johnson syndrome by the pattern of urinary coproporphyrin excretion and by the results of bromsulphthalein (BSP) clearance testing. Rotor syndrome is considered a benign condition that does not require treatment. The jaundice is typically mild and intermittent, and affected individuals have a normal life expectancy with no progression to liver disease. No specific therapy is needed, though it is important to establish the correct diagnosis to avoid unnecessary invasive investigations. Genetic counseling may be offered to affected families. The condition appears to be more prevalent in Filipino populations, though cases have been reported worldwide.

Common questions about Rotor syndrome