Making precise molecular genetic diagnoses in inherited kidney diseases is important. Gee et al. describe families with end-stage renal disease secondary to a presumed diagnosis of a nephronophthisis-related ciliopathy (NPHP-RC), in whom a combination of approaches allowed genetic diagnoses to be made. New genetic approaches to the diagnosis of childhood renal failure are becoming mainstream and will hopefully improve patient management, avoid clinical misdiagnoses, reduce the need for invasive investigations, and allow screening of at-risk relatives.