DARU Journal of Pharmaceutical Sciences74SCREENING OF 6-PYRUVOYL-TETRAHYDROPTERIN SYNTHASE ACTIVITY DEFICIENCY AMONG HYPERP HENYLALANINEMIC PATIENTS911DURDI QUJEQ20151006A deficiency of the phenylalanine hydroxylase activity or its cofactor tetrahydrobiopterin maylead to hyperphenylalamnemia and as a result, loss of IQ, poor school performance, andbehavior problems occurs. Deficiency in 6-pyruvoyl-tetrahydropterin synthase activity is themajor cause of tetrahydrobiopterin deficient phenylketonuria. In this study, blood specimensfrom 165 healthy volunteers and 127 children with phenylketonuria were used to determinethe 6-pyruvoyl-tetrahydropterin synthase activity. It was found that the activity of 6-pyruvoyl- tetrahydropterin synthase was decreased in comparison with control [23.46 +/-2.94, (mean +/- SD, mmol/ ml/h, n=I27) vs. 127.63 +/- 4.52, n=165), p<0.05]. Results ofthis study indicate that examination of 6-pyruvoyl-tetrahydropterin synthase activity is helpfuland may lead to the diagnosis cause of hyperphenylalaninemia.https://daru.tums.ac.ir/index.php/daru/article/view/87https://daru.tums.ac.ir/index.php/daru/article/download/87/87