[Renal and enteral elimination of coproporphyrin isomers in Rotor's syndrome. A family study].

Urinary and fecal total, isomer I, and isomer III coproporphyrin excretion of a Rotor's syndrome patient and his family were determined. The propositus showed increased urinary total coproporphyrin excretion (248 micrograms/24 h) and a shift of the coproporphyrin isomer I/III relation (70%/30%). The propositus's father and two siblings also had elevated renal excretion of coproporphyrin I. Total coproporphyrin excretion was enhanced only in the propositus's father and one sibling, while being normal in another sibling. All family members that could be investigated showed considerably decreased fecal porphyrin excretion. In Rotor's syndrome porphyrin excretion is mainly renal. The coproporphyrin isomer I/III relation is shifted towards isomer I. Phenotypically normal relatives with normal bilirubin plasma levels may have alterations in both their renal and enteral coproporphyrin excretion.