Rotor syndrome (also known as Rotor type hyperbilirubinemia)[2] is a rare cause of mixed direct (conjugated) and indirect (unconjugated) hyperbilirubinemia, relatively benign, autosomal recessive[3] bilirubin disorder characterized by non-hemolytic jaundice due to the chronic elevation of predominantly conjugated bilirubin.

[2] Rotor type hyperbilirubinemia is a distinct yet similar disorder to Dubin–Johnson syndrome[1] – both diseases cause an increase in conjugated bilirubin, but Rotor syndrome differs in that it is a result of impaired hepatocellular storage of conjugated bilirubin that leaks into plasma causing hyperbilirubinemia.

[5] Rotor syndrome is caused by mutations in two proteins responsible for transporting bilirubin and other compounds from the blood to the liver to be metabolized and cleared from the body.

In the liver, bilirubin is dissolved in a digestive fluid called bile and then excreted from the body.

[2] Imaging studies cannot diagnose Rotor syndrome but can help rule out other diseases that cause hyperbilirubinemia.

[2] Jaundice is a lifelong finding, but the disease is not associated with morbidity or mortality, and life expectancy is not affected.

[2] Distinguishing Rotor syndrome from other more serious disorders is important to avoid unnecessary workup and interventions.