- Mutations of the UMOD gene are responsible for medullary cystic kidney disease 2 and familial juvenile hyperuricaemic nephropathy. Hart, T.C., Gorry, M.C., Hart, P.S., Woodard, A.S., Shihabi, Z., Sandhu, J., Shirts, B., Xu, L., Zhu, H., Barmada, M.M., Bleyer, A.J. J. Med. Genet. (2002)