Autosomal dominant polycystic kidney disease: early diagnosis and data for genetic counselling.

Because of the onset of symptoms in patients with autosomal dominant polycystic kidney disease is generally delayed until adulthood, genetic counseling is imprecise. In an attempt to identify patients early, 261 offspring of subjects with the gene for polycystic disease were tested. Agreement between the results of excretory urography with nephrotomography and radionuclide imaging was excellent. In the 15-19 year age group, polycystic kidney disease was diagnosed in only 30% of 33 subjects at risk, whereas the expected figure was 50%. The disease was diagnosed in 57% of 228 subjects at risk who were aged over 19. When the probands were excluded, this figure was 43% and did not differ significantly from the expected 50%. These data suggest that persons at risk aged over 19 years who have normal urograms and radionuclide images have less than a 5% chance of having inherited the gene for polycystic kidney disease.