新疆地区汉族苯丙酮尿症患儿苯丙氨酸羟化酶基因突变分析

Analysis of phenylalanine hydroxylase gene mutations in Han ethnic children with phenylketonuria of Xinjiang region

目的分析新疆地区汉族苯丙酮尿症(PKU)患儿苯丙氨酸羟化酶(PAH)基因的突变规律和特点。方法用PCR产物直接测序法、基因芯片捕获和二代高通量测序技术对71例汉族PKU患儿及其父母的PAH基因启动子、第1~13外显子及其旁侧内含子等区域进行PAH基因突变分析,并与西北4省及日本、欧洲等进行比较。结果在新疆地区71例汉族PKU患儿142条PAH等位基因中检测出37种突变基因,总检出率为90.1%(128/142),且以错义突变(64.9%)、剪接位点突变(13.5%)、无义突变(13.5%)为主,大部分突变主要分布在第7、6、3、12、2、11外显子和第4内含子中,最常见的错义突变是R243Q(21.8%)、R53H(7.7%);最常见的剪接位点突变为EX6-96A>G(6.3%)、IVS4-1G>A(4.9%)和V399V(4.2%),最常见的无义突变为R111X(4.9%)、Y356X(4.9%)。新疆地区汉族PKU患儿R53H突变的检出率(7.7%)高于西北其他4省,且发现一PAH基因新突变P225S(c.673C>T)。结论新疆地区汉族PKU患儿PAH基因突变构成接近于西北其他4省,而与欧洲、日本等完全不同,具有其独特保守的地域特征。

Objective To investigate the characteristics of phenylalanine hydroxylase （PAH） gene mutations in Han ethnic children with phenylketonuria of Xinjiang region. Methods The mutations in the promoter, exons 1-13 and flanking introns of PAH genes from 71 Hun ethnic PKU children and their parents of Xinjiang region were detected by PCR, DNA sequencing and high-throughput targeted sequencing, and the obtained results were compared with those from other four provinces in northwest of China, Japan and Europe. Re- suits A total of 37 kinds of mutations, including missense mutation, splice site mutation, nonsense mutation, deletion mutation and frameshift mutation, were detected in 90.1% （128/142） of PAH alleles from 71 Hun ethnic PKU children of Xinjiang region. Most mutations existed in exons 7, 6, 3, 12, 2 and 11 and intron 4 of PAH gene. The most common missense mutations were R243Q （21.8%） and R53H （7.7%）. The most common splicing sites were EX6-96A 〉 G（6.3% ）, IVS4-1G 〉 A （4.9%） and V399V （4.2%）. Moreover,The most common nonsense mutations were RlllX（4.9% ） and Y356X（4.9% ）. The detection rate of R53H mutation （7.7%） in Han ethnic PKU children of Xinjiang region was significantly higher than that in other 4 provinces of northwest of China, and a novel PAH gene mutation P225S（ c. 673C 〉 T） was found. Conclusion The mutation spectrum of PAH gene in Hun ethnic PKU children of Xinjiang region is similar to that in other 4 provinces of northwest of China, but significantly different from that of Japa- nese and European population, which displays a distinct and conservative characteristic.