The Use of Genetic Testing in Nephrolithiasis Evaluation: A Retrospective Review From a Multidisciplinary Kidney Stone Clinic

To describe genetic and clinical characteristics for patients undergoing genetic testing at our multidisciplinary kidney stone clinic. A retrospective review was performed on patients evaluated in our stone clinic and referred to genetics between 2018 and 2022. Patient demographic, clinical, stone, and genetic data were included. We assessed the specific variants identified in our cohort, both those with a pathogenic association and variants of unknown significance. Of 825 patients seen in our stone clinic from 2018-2022, 50 patients were referred to genetics. Among these patients, 33/50 (66%) underwent genetic testing and were included in the analysis. Of those who underwent genetic testing, a variant was identified in 19/33 (58%) patients, and 9/33 (27%) of these were a known pathogenic variant. Among patients with a pathogenic variant identified, the majority had a family history of stones (55.6%), calcium-based stones (77.8%), had their first stone prior to age 18 (66.7%), were recurrent stone formers (100%), and had been managed medically (88.9%) or surgically (88.9%) prior to testing. When comparing patients with a pathogenic variant, variants of unknown significance, and no variant, there were no significant differences in demographic or clinical parameters. In our stone practice, more than half of patients who underwent genetic testing were found to have a variant. However, the majority of these variants were of unknown significance. Further evaluation regarding how genetic testing can impact nephrolithiasis management is needed.