HNF1B and autosomal dominant medullary cystic kidney disease with or without hyperuricemia: Reduced UMOD expression in ADTKD-HNF1β patients may also have implications for renal electrolyte handling since UMOD has been demonstrated to activate NKCC2, NCC, transient receptor potential melastatin type 6 (TRPM6), and TRP vanilloid type 5 (TRPV5) activity [54, 56, 75, 83].