Alpha thalassaemia: a potential source of error in DNA linkage studies for adult polycystic kidney disease.

DNA polymorphisms associated with adult polycystic kidney disease and detected by restriction enzymes PvuII and RsaI were sought in 18 members of a Greek Cypriot family. The adult polycystic kidney disease (APKD) defect was shown to segregate with a specific 3'HVR PvuII DNA polymorphism and enabled exclusion of APKD in two children incorrectly diagnosed by ultrasound. An unusual problem of the DNA linkage approach in detection of APKD is illustrated. This occurred after coinheritance of alpha+ thalassaemia and APKD, which resulted in an altered band size for the (+) RsaI restriction fragment length polymorphism.