Genetic Testing in Peritoneal Dialysis: Applying International Recommendations to Identify Missed Diagnostic Opportunities

Abstract

Introduction: Chronic kidney disease (CKD) of unknown etiology remains frequent and delays diagnosis and targeted therapy. International recommendations define when genetic testing should be offered, but their application has not been described in patients already established on kidney replacement therapy. Peritoneal dialysis (PD) patients are comparatively young, mostly transplant candidates and closely followed, and may particularly benefit from diagnostic reassessment.

Methods: Retrospective observational study including all patients enrolled in a hospital-based PD programme in January 2025. Demographics, comorbidities, CKD etiology, biopsy findings, family history, transplant status and prior genetic evaluation were extracted from source records. Criteria for genetic testing, based on international recommendations, were defined before record review.

Results: Sixty-six patients were included (62.1% male; mean age 54.5 ± 15.9 years), with a mean nephrology follow-up of 14.3 ± 9.6 years. Forty-two patients (63.6%) were actively listed for transplantation. Kidney biopsy was available in 21 patients (31.8%). In the remaining 45 (68.2%) the etiology had been attributed clinically and never revised. Family history was inconsistently documented. Twenty-four patients (36.4%; 95% CI 25.5–48.5) met at least one criterion for genetic testing, but only five (20.8% of those eligible; 7.6% of the cohort) had been evaluated, leaving 19 unmet indications.

Conclusion: One in three PD patients fulfilled criteria for genetic testing and four of five of these had never been tested, despite more than a decade of follow-up. Kidney replacement therapy should not be treated as the endpoint of etiological investigation: in PD, where most patients are transplant candidates, genetic evaluation remains clinically useful.