PRTFDC1 is a member of the purine/pyrimidine phosphoribosyltransferase family. It can bind GMP, IMP and alpha-D-5-phosphoribosyl 1-pyrophosphate (PRPP). The epigenetic silencing of PRTFDC1 by hypermethylation of the CpG island leads to a loss of PRTFDC1 function, which might be involved in squamous cell oral carcinogenesis. PRTFDC1 is a genetic modifier of HPRT-deficiency in the mouse and has important implications for unraveling the molecular etiology of lesch-Nyhan disease(LND). LND is a severe X-linked neurological disorder caused by a deficiency of hypoxanthine phosphoribosyltransferase. PRTFDC1 has a low, barely measurable phosphoribosyltransferase activity (in vitro).