Study On The Mutations Of Phenylalanine Hydroxylase Gene In Patients With Phenylketonuria In Shanxi

BackgroundPhenylketonuria (PKU) is one of the curable hereditary diseases. The incidence of PKU in China is1/11572, while the incidence of PKU in shanxi province is1/3425from2004to2009. The ratio is much higher than that of the national average. The key measure for treatment of PKU is early diagnosis. Taking long time, referring only to infant and having no power to early diagnosis were the chief defect to those methods. Especially for families have given birth to PKU babies, the probability of having a PKU babies again is25%. Irrational births could result in a tragedy once more. By studying of the hot spots, characteristics and frequencies of PAH gene mutations in PKU patients in shanxi province, PAH gene bank which can lay the foundation of prenatal diagnosis, treatment, genetic counseling and TORCH for PKU patients was built.ObjectiveIn this article, we will research the mutation of PAH genes in PKU patients, and work out the best diagnosis scheme. We propose to provide an effective molecular profiling data in shanxi province. We also propose to discuss the molecular mechanism of PAH genes mutation, and provide some evidence for gene diagnosis, prenatal diagnosis, and new medicament research.Methods1、Exon3、6、7、11、12of PAH gene were amplified and sequenced. Then these sequences were compared with those of the mild PHA gene. Finally, we found all mutation spot of PHA gene in PKU patients;2、The hot mutation spot (c.611A>G) in patients with classic PKU were detecting by ARMS. In this study,97patients with PKU and158health kids collected since May2007to May2011in shanxi province were included;3、HRM was used to detect the hot mutation spot (c.728G>A) in patients with PKU at the first time.Results1、Three silent mutation, four mutation types, and16mutation spot were detected in exon3、6、7、11、12of PAH gene in PKU patients and normal children. What more, H64>Tfs was a new mutation spot and both Y204C and R243Q were hot mutation spots which belong to shanxiprovince2The hot mutation spot c.611A> G in exon6was found in10out of70cases with PKU.The result of mutation spot of c.611A>G in exon6with the ARMS test are completelyconsistent with the DNA sequencing result3PCR-HRM technology was used to detect c.728G> A mutation in exon7in88classicaltype PKU patients and20cases had c.728G> A mutation in exon7, including2homozygousmutations and18heterozygous mutations. The results detected by PCR-HRM is in goodagreement with the result obtained by direct sequencing.Conclusion1According to the study, we could provide an effective molecular profiling data in shanxiprovince and enrich the PKU database2The method of ARMS is repeatable, specific and stable, and can be used as a simple,rapid, and sensitive method to identified the mutation hot spots of PAH3HRM is a simple, rapid and sensitive gene analysis method which can differentiatedifferent SNP sites and different genes. It is also a method which is fit for clinical screening andtreatment testing.