DETERMINATION OF EXON 7 MUTATION IN PAH GENE OF CLASSICAL PHENYLKETONURIA AND IDENTIFICATION OF NOVEL MUTATION IN INNER MONGOLIA

Objective: To study phenylketonuria(PKU) gene mutation character in Inner Mongolia area and provide foundation for gene diagnosis. Methods: Exon7 of the phenylalanine hydroxylase(PAH) gene was analyzed in 22 children affected with classical PKU from Inner Mongolia by using PCR-single strand conformation polymorphism (PCR-SSCP) technique and DNA direct sequencing. Results: Four missense mutations(i.e. R243Q, R252Q, R261Q and G239D)and one splice site muation(IVS7nt2) were identified. The mutation frequencies are 8/44,1/44?1/44?1/44?1/44, respectively. The mutation G239D(G→A) was demonstrated as novel mutation in comparison with the PAH mutation database. Conclusion:Mutation and their frequencies in exon7 of PAH gene of PKU in the people of Inner Mongolia are similar to those in the northeastern people, but such characteristic is different from that in the southern people. This finding has theoretical and practical value for increasing gene diagnosis rate in Inner Mongolia.\;