Nephrectomy in autosomal dominant polycystic kidney disease: A consensus statement of the ERA Genes & Kidney Working Group

\ua9 2025 The Author(s). A substantial number of patients with autosomal dominant polycystic kidney disease (ADPKD) undergo a nephrectomy, especially in workup for a kidney transplantation. Currently, there is no evidence-based algorithm to guide clinicians about which patients should undergo nephrectomy, the optimal timing of this procedure, or the preferred surgical technique. This systematic review-based consensus statement aimed to answer important questions regarding nephrectomy in ADPKD. A literature review was performed and extended to a meta-analysis when possible. For this purpose, PubMed and EMBASE were searched up to May 2024. Fifty-four publications, describing a total of 2391 procedures, were included. In addition, an exploratory questionnaire was sent to urologists, nephrologists, and transplant surgeons. These sources were used to develop practice points about indications, complications, mortality, and timing and technique of nephrectomy. In addition, data on renal embolization as a potential alternative to nephrectomy were explored and summarized. To reach consensus, practice points were defined and improved in three Delphi survey rounds by experts of the European Renal Association Working Group Genes & Kidney and the European Association of Urology Section of Transplantation Urology. A total of 23 practice points/statements were developed, all of which reached consensus. Among others, it was deemed that nephrectomy can be performed successfully for various indications and is an intermediate risk procedure with acceptable mortality and minimal impact on kidney graft function when performed before, in the same session or after transplantation. The complication rate seems to increase when the procedure is performed as an emergency. During the workup for transplantation, patient complaints should be assessed routinely by questionnaires to indicate symptom burden. Deciding on the need for nephrectomy and exploring potential alternatives such as kidney embolization should be a process of shared decision-making, preferably after multidisciplinary consultation

Characterization of the Cystic Phenotype Associated with Monoallelic <em>ALG8</em> and <em>ALG9</em> Pathogenic Variants

Copyright \ua9 2025 by the American Society of Nephrology. Background: Autosomal dominant polycystic kidney disease (ADPKD) is a common, inherited nephropathy often resulting in kidney failure. It is genetically heterogeneous; along with the major genes, PKD1 and PKD2, at least 8 others have been suggested. ALG8 pathogenic variants have been associated with autosomal dominant polycystic liver disease and implicated in ADPKD, while ALG9 has been suggested as an ADPKD gene, but details of the phenotypes and penetrance are unclear. Methods: We screened &gt;3900 families with cystic kidneys and/or livers using global approaches to detect ALG8 or ALG9 pathogenic variants. In addition, population cohorts with sequence data (Genomics England 100kGP (100kGP), UK Biobank (UKBB), and Mayo Clinic Biobank (MCBB)), were screened for ALG8/ALG9 pathogenic variants. Results: Multicenter screening of individuals with polycystic kidney and/or liver disease identified 51 (1.3%) ALG8 (7 multiplex) and 23 (0.6%) ALG9 (5 multiplex) families; frequencies that were ∼10x and ∼24x greater than non-polycystic kidney disease (PKD) controls. Analysis of individuals with PKD phenotypes in 100kGP, UKBB, and MCBB identified 9 ALG8 (0.39%) and 9 ALG9 (0.39%) families, an enriched frequency over controls. Two individuals had PKD1 and ALG8 pathogenic changes. Eighty-nine percent of individuals with ALG8 mutations with imaging in the entire MCBB had kidney cysts (56%, &gt;10 cysts), with greater median kidney and liver cyst numbers than controls. For ALG9, 78% had kidney cysts (27%, &gt;10 cysts). Individuals with ALG8 mutations typically had mild cystic kidneys with limited enlargement. Liver cysts were common (71%) with enlarged livers (&gt;2L) found in 11/62 patients although surgical intervention was rare. The ALG9 kidney phenotype was also of mild cystic kidneys but enlarged livers were rare; for both genes chronic kidney disease or kidney failure were rare. Conclusions: ALG8 and ALG9 are defined as cystic kidney/liver genes but with limited penetrance for lower eGFR