Sequencing initiatives in CLCN5-negative patients with clinical features of Dent disease led to the discovery of mutations in OCRL1 (Xq26.1) in this population.3 While sharing the renal manifestations present in Dent disease type 1, patients harboring OCRL1 mutations display a different pattern of extrarenal manifestations, including variable cognitive impairment, subclinical cataracts and umbilical hernias. This evidence concerns the gene CLCN5 and Dent disease type 1.