Evolving role of genetic testing for the clinical management of autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is caused primarily by mutations of two genes, PKD1 and PKD2. In the presence of a positive family history of ADPKD, genetic testing is currently seldom indicated as the diagnosis is mostly based on imaging studies using well-established criteria. Moreover, PKD1 mutation screening is technically challenging due to its large size, complexity (i.e. presence of six pseudogenes with high levels of DNA sequence similarity) and extensive allelic heterogeneity. Despite these limitations, recent studies have delineated a strong genotype-phenotype correlation in ADPKD and begun to unravel the role of genetics underlying cases with atypical phenotypes. Furthermore, adaptation of next-generation sequencing (NGS) to clinical PKD genetic testing will provide a high-throughput, accurate and comprehensive screen of multiple cystic disease and modifier genes at a reduced cost. In this review, we discuss the evolving indications of genetic testing in ADPKD and how NGS-based screening promises to yield clinically important prognostic information for both typical as well as unusual genetic (e.g. allelic or genic interactions, somatic mosaicism, cystic kidney disease modifiers) cases to advance personalized medicine in the era of novel therapeutics for ADPKD.