tissue culture fibroblasts derived from patients with lesch-nyhan disease ( congenital hyperuricosuria ) have a reduced imp : pyrophosphate phosphoribosyltransferase ( ec 2.4.2.8 ) activity and therefore incorporate , as detected by radioautography , much smaller amounts of tritiated hypoxanthine or guanine into cell nuclei and cytoplasm than do normal cells .
C0016030
fibroblasts
C0007634
normal cells