Presymptomatic testing for adult onset polycystic kidney disease in at-risk kidney transplant donors.

Autosomal dominant adult-onset polycystic kidney disease (ADPKD) is estimated to have an incidence of 1/1,000 and accounts for approximately 10% of all end-stage renal disease in the United States. While relatives are attractive as renal donors due to their availability and the improved transplant success associated with living-related donors, they may coincidentally be at risk for ADPKD. Accurate presymptomatic testing for at-risk potential donors is critical for both the donor and the recipient. We report here 2 families in which presymptomatic testing for ADPKD was accomplished by DNA linkage analysis on several potential renal donors prior to transplant. This resulted in the protection of both donors and recipients by preventing the transplantation of a kidney affected by ADPKD. Thorough counseling prior to DNA analysis (including discussion of accuracy and possible testing outcomes of presymptomatic diagnosis of ADPKD, diagnosis of noncarrier status, false paternity, and non-informative study) was essential to provide informed consent and preserve confidentiality within the family. Confidentiality for potential donors found presymptomatically to be affected (with a 94% or greater probability) was especially difficult to maintain.