Ottlewski I, et al. - In this single-center study, researchers examined patients on the kidney transplantation (KT) waitlist, via a systematic evaluation, in order to investigate for rare genetic causes in patients with undetermined end-stage renal disease (ESRD). Mutations in genes encoding components of the glomerular filtration barrier were evident in all cases. In 35 of the 142 patients of the waitlist cohort, they detected hereditary nephropathies, including autosomal dominant polycystic kidney disease. Genetic diagnostics proved beneficial in significantly unraveling undetermined ESRD cases before KT. A robust and specific renal diagnosis may be offered by genetic analysis, in addition to optimization of pre- and post-KT management, in cases without renal histology or in the presence of unspecific histological conditions, such as hypertensive nephrosclerosis, focal segmental glomerulosclerosis or thrombotic microangiopathy.