[Mutations of the phenylalanine hydroxylase gene in phenylketonuria patients from Shaanxi].

[phenylketonuria]

To investigate the feature of phenylalanine hydroxylase (PAH ) gene mutations and provide guidance for genetic and prenatal diagnosis of patients with phenylketonuria from Shaanxi .For 55 patients whose blood Phe concentration was over 2 .0 mg /dL , potential mutations in 13 exons and flanking sequences of the PAH gene were detected by PCR and DNA sequencing .A total of 98 mutations were detected in 110 PAH alleles , with the detection rate being 89 .10 %. Nine mutations have been identified in exon 7 , which accounted for 33 .67 % of all . Exon 12 (14 .29 %) and exon 3 (12 .24 %) have followed . Thirty eight mutations , locating in exon 2 -exon 12 and the flanking sequence , were detected in the 55 PKU patients . p .R 243 Q (24 .49 %) was the commonest mutation , whilstp .A 47 E , p .I 65 S and p .A 259 T were first discovered in China . After querying international databases including PAHdb and HGMD , the p .C 3 34 X was verified as the novel PAH gene mutation .The mutation spectrum of the PAH gene in Shaanxi has been identified . And a novel mutation has been identified . This may facilitate the diagnosis of PKU in the future .