Genetic Evaluation Practices in Living Kidney Donor Candidates

Introduction Although genetic testing is increasingly used in evaluating living kidney donor (LKD) candidates and recipients, objective data on genetic testing practices are limited. This study aimed to describe current genetic testing practices in LKD evaluation using data from the international Living Donor Genetic registry. Methods A REDCap registry was developed to collect cross-sectional, de-identified information on LKD candidates and genetic test results. Participating centers registered candidates meeting at least one of the following criteria: 1) underwent genetic testing; 2) family history of genetic kidney disease; and/or 3) were evaluated to donate to a biologically related recipient with kidney disease of unknown etiology. Data were collected between 06/01/2023 and 11/10/2025. Results Among 1,259 LKD evaluations from 24 centers (10 U.S., 14 international), genetic testing was performed in 295 (23.4%). U.S. donor candidates were younger (median 39 vs. 48 years, p<0.001). Testing strategies differed by region: international centers predominantly used recipient-first testing (92.1%), whereas U.S. centers more often performed direct LKD testing (61.5%; p<0.001). These differences persisted after excluding APOL1 testing, with direct LKD candidate testing remaining more common in U.S. (34.0% vs. 7.9%; p<0.001). Among tested LKD candidates, 20.7% (61/295) were not approved for donation, with 7.8% (23/295) attributed to genetic findings. In multivariable analysis, younger donor age was independently associated with LKD non-acceptance (aOR 0.89 per-year; 95%CI, 0.83-0.95; p<0.001). Conclusions Genetic testing practices vary substantially across regions, with U.S centers favoring direct LKD testing and international centers using recipient-first approaches. Younger donor candidate age was independently associated with non-acceptance.