Upper urothelial tumours and the Balkan nephropathy. Inference from the study of a family pedigree.

In an area heavily affected by both Balkan nephropathy (BN) and upper urothelial tumours (UUT), an outbreak of UUT (followed later by BN) affected at least four of five siblings. Their cousins developed BN in a high proportion but no one of them had any sign of UUT. It has been suggested that host factors determine the outcome of exposure to the same agent(s) responsible for both diseases.