目的 分析菏泽市苯丙酮尿症(PKU)患儿苯丙氨酸羟化酶(PAH)基因突变特点,为深入开展PKU的诊断以及进一步的基因治疗提供科学依据。方法 采用高通量测序技术对临床确诊且自愿进行基因检测的PKU患儿的遗传代谢病相关基因进行检测,检出位点采用sanger测序进行验证及父母验证。结果 28个患者经测序分析后,共检出致病变异位点53个,总检出率为94.6%。其中25个患者检测到2个致病突变(89.3%),3个患者检测出1个突变位点(10.7%)。在53种变异类型中,错义突变38种(71.7%)、剪接突变4种(7.5%)、无义突变11种(20.8%)。变异位点分布在PAH基因第2、3、6、7、9~11外显子以及第4内含子区。外显子区变异位点50个(94.3%),内含子区变异位点3个(5.7%)。经典型PKU患儿以 c.1068C＞A为主,轻度PKU患儿以c.158G＞A、c.728G＞A为主,轻度高苯丙氨酸血症(HPA)以c.158G＞A及c.1068C＞A为主。c.158G＞A、c.728G＞A和c.1068c＞A的检出人数较多,c.158G＞A在轻度PKU及轻度HPA患儿中检出,平均Phe浓度为860.74 μmol/L,c.728G＞A在经典型PKU、轻度PKU患儿中检出,平均Phe浓度为879.51 μmol/L,c.1068C＞A在经典型PKU及轻度HPA患儿中检出,平均Phe浓度为1 098.44 μmol/L。结论 菏泽市PKU患儿PAH基因突变以c.158G＞A、c.728G＞A及c.1068C＞A突变为主。

Objective To analyze the mutation characteristics of phenylalanine hydroxylase (PAH) gene in children with phenylketonuria (PKU) in Heze,Shandong,in order to provide scientific reference for further diagnosis and gene treatment of PKU. Methods For children with PKU who were clinically diagnosed and voluntarily underwent genetic testing,high-throughput sequencing technology was used to detect genes related to genetic metabolic diseases in patients,and the detected loci were verified by sanger sequencing and parental verification. Results A total of 53 pathogenic variants were detected in 28 children,of which 25 children were detected with 2 definite pathogenic alleles (89.3%),and 3 patients was detected with 1 variant allele gene (10.7%). Among the 53 mutation types,there were 38 missense mutations (71.7%),4 splicing mutations (7.5%) and 11 nonsense mutations (20.8%). The mutation sites were distributed in the 2^nd,3^rd,6^th,7^th,9^th-11^th and 4^th intron regions of PAH gene. There were 50 (94.3%) variation sites in the exon region and 3 (5.7%) variation sites in the intron region. In children with typical PKU,c.1068C>A was the predominant variation site. While the variation sites of children with mild PKU mainly included c.158G＞A,c.728G>A,and children with mild HPA were presented with variation sites of c.158G>A and c.1068C>A. The detection of c.158G＞A,c.728G＞A and c.1068c＞A was high. c.158G＞A was detected in children with mild PKU and mild HPA,with a mean Phe concentration of 860.74 μmol/L. And c.728G＞A was detected in children with typical PKU and mild PKU,with a mean Phe concentration of 879.51 μmol/L. c.1068C＞A was detected in children with typical PKU and mild HPA,with a mean Phe concentration of 1 098.44 μmol/L. Conclusion The main mutations of PAH gene in children with PKU in Heze include c.158G>A,c.728G>A and c.1068C>A.