OCRL and Dent disease: Dent's disease may be caused by either inactivating mutations in CLCN5 (OMIM #300008), which is located on chromosome Xp11.22 and encodes a 746 amino-acid electrogenic Cl-/H+ exchanger (ClC-5) [5,14], or the OCRL1 gene, which is located on chromosome Xq25 and encodes the phosphatidylinositol 4,5-biphosphate 5 -phosphatase OCRL1 [13].