Autosomal dominant tubulointerstitial kidney disease-1 (ADTKD1) is an adult-onset slowly progressive renal disease characterized by elevated serum uric acid (hyperuricemia) due to low fractional excretion of uric acid, defective urinary concentrating ability, 'bland' urinary sediment, and progression to end-stage renal failure. Some patients may develop gouty arthritis, arterial hypertension, polydipsia/polyuria, or mild proteinuria. The onset of symptoms is usually in the third or fourth decade, although earlier and later onset have been reported. Renal ultrasound may show small or hyperechogenic kidneys. Renal biopsy shows variable abnormalities, including tubular atrophy, interstitial fibrosis, microcystic dilatation of the tubules, thickening of tubular basement membranes, medullary cysts, and secondary glomerulosclerotic or glomerulocystic changes with abnormal glomerular tufting. The median age at onset of end-stage renal disease (ESRD) is 56 years (range 50-65). There is significant inter- and intrafamilial variability, as well as incomplete penetrance, which hampers diagnosis. [From OMIM]