POS-428 PROTEIN-TRUNCATING PKD1 MUTATIONS YET MILD AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE IS UNDER-RECOGNIZED

Progression of autosomal dominant polycystic kidney disease (ADPKD) is highly variable between patients. On average, protein-truncating PKD1 mutations are associated with the most severe kidney disease among all mutation classes, yet within family disease variability is a recognized feature of ADPKD. The penetrance of protein-truncating PKD1 mutations cannot be adequately evaluated if only index probands with severe disease are tested. Here, we evaluated the patients with protein-truncating PKD1 mutations yet mild kidney disease from the extended Toronto Genetic Epidemiologic Study of Polycystic Kidney Disease.