UMOD and autosomal dominant medullary cystic kidney disease with or without hyperuricemia: Another example of complex pathogenic mechanism is UMOD (uromodulin, an inhibitor of crystallization of calcium in urine), whose pathogenic variants are responsible of medullary cystic kidney disease, but some common variants have been seen to facilitate the expression of TRPV5 (22), therefore having a protective effect against nephrolithiasis.