When should the nephrologist think about genetics in patients with glomerular diseases?

Abstract

This review discusses the significance of genetics in diagnosing glomerular diseases. Advances in genetic testing, particularly next-generation sequencing, have improved the accessibility and accuracy of diagnosing monogenic diseases, allowing for targeted gene panels and whole-exome/genome sequencing to identify genetic variants associated with glomerular diseases. Key indicators for considering a genetic cause include the age of onset, extrarenal features, family history, and inconclusive kidney biopsy results. Early-onset diseases, for instance, have a higher likelihood of being genetically caused, while extrarenal manifestations can also suggest an underlying genetic condition. A thorough family history can reveal patterns of inheritance that point to monogenic causes, although complexities like incomplete penetrance, skewed X inactivation and mosaicism can complicate the assessment. Also, autosomal recessive conditions imply asymptomatic parents, making genetic suspicion less likely, while de novo mutations can occur without any family history, further obscuring genetic assessment. Focal segmental glomerulosclerosis (FSGS) is characterized by podocyte injury and depletion, presenting in various forms, including primary, genetic, and secondary FSGS. Accurate classification of FSGS patients based on clinical and histological features is essential for guiding treatment decisions, optimizing therapeutic plans, avoiding unnecessary immunosuppression, and predicting relapse risk after kidney transplantation. Overall, a clinicopathological approach, enriched by genetic testing, offers a precise framework for diagnosis and management in glomerular diseases. Future directions for research and clinical practice include potential advancements in genetic testing and personalized medicine, which could further improve diagnostic precision and individualized treatment strategies.

Keywords: FSGS; genetic; genetic testing; glomerular; proteinuric.

Figure 1:

Key features to elicit a request for a genetic test for glomerular disease.