BACKGROUND: PHENYLKETONURIA (PKU) IS AN INHERITED NEWBORN METABOLIC DISEASE CAUSED BY DEFICIENCY OF PHENYLALANINE HYDROXYLASE (PAH). THIS ENZYME IS NECESSARY TO METABOLIZE THE AMINO ACID PHENYLALANINE TO THE AMINO ACID TYROSINE.
PAH DEFICIENCY LEADING TO ACCUMULATION OF PHENYLALANINE IN BLOOD. UNTREATED PKU CAN LEAD TO SEVER MENTAL RETARDATION IN NEWBORNS. MATERIAL AND METHODS: BLOOD SAMPLES WERE COLLECTED ON FILTER PAPER WATMAN 903 FROM 77000 NEWBORNS IN ISFAHAN PROVINCE IN 1391-1392.