石家庄市苯丙氨酸羟化酶缺乏症的基因突变研究

Study on gene mutation of phenylalanine hydroxylase deficiency in Shijiazhuang

目的分析石家庄市新生儿疾病筛查诊治中心确诊的苯丙氨酸羟化酶缺乏症(PAHD)患儿中PAH基因的突变规律及特点,为石家庄市PAHD的产前诊断、治疗提供有力的科学依据。方法收集在石家庄市新生儿疾病筛查诊治中心确诊的PAHD患儿67例作为研究对象,提取患儿及其父母外周血DNA标本进行二代测序,测序范围包括13个外显子和外显子上、下游200个碱基对的内含子,对可疑突变位点进行一代测序验证,可疑大片段缺失重复进行多重连接探针扩增验证。结果67例PAHD患儿中61例患儿PAH基因检测到2个突变位点,3例患儿PAH基因检测到3个突变位点,3例患儿PAH基因只检测到1个突变位点。67例PAHD患儿中共检测到44种突变,134个PAH基因突变位点。高频突变位点主要是c.158G>A、c.728G>A、c.331C>T。16例经典型苯丙酮尿症患儿中c.1068C>A和c.331C>T突变频率最高(15.63%,5/32);11例轻度苯丙酮尿症患儿中c.721C>T突变频率最高(18.18%,4/22);40例轻度高苯丙氨酸血症患儿中c.158G>A突变频率最高(35.00%,28/80)。检测出的134个突变位点中有3个尚未见报道,分别为c.912+5G>T、c.61-1G>A和c.630T>G。结论石家庄市PAHD患儿PAH基因突变以复合杂合突变为主,该研究明确了石家庄市PAHD患儿基因的突变类型与特点,为深入开展PAHD的诊断及产前诊断、治疗和遗传咨询提供了有力的依据和帮助。

Objective To analyze the mutation rule and characteristics of PAH gene in children with phenylalanine hydroxylase deficiency(PAHD)diagnosed by Shijiazhuang Neonatal Disease Screening and Diagnosis Center,so as to provide a strong scientific basis for prenatal diagnosis and treatment of PAHD.Methods A total of 67 children with PAHD diagnosed in Shijiazhuang Neonatal Disease Screening and Diagnosis Center were collected.Peripheral blood DNA samples of the children and their parents were extracted for second-generation sequencing.The sequencing range included 13 exons and introns of 200 base pairs upstream and downstream of exons.The suspected mutation sites were verified by first-generation sequencing,and the suspected large deletion repeats were verified by multiplex ligation probe amplification.Results In 67 cases of PAHD,2 mutation sites were detected in 61 cases,3 mutation sites were detected in 3 cases,only one mutation site was detected in 3 cases.A total of 44 mutations and 134 PAH gene mutation sites were detected in 67 cases of PAHD.The high frequency mutation sites were c.158G>A,c.728G>A,c.331C>T.The mutation frequency of c.1068C>A and c.331C>T was the highest in 16 children with classic phenylketonuria(15.63%,5/32).The mutation frequency of c.721C>T was the highest in 11 children with mild phenylketonuria(18.18%,4/22).The mutation frequency of c.158G>A was the highest in 40 children with mild phenylalaninemia(35.00%,28/80).3 of the 134 mutation sites have been rarely reported,namely c.912+5G>T,c.61-1G>A and c.630T>G,respectively.Conclusion The PAH gene mutations in children with PAHD in Shijiazhuang are mainly compound heterozygous mutations.This study clarifies the types and characteristics of gene mutations in children with PAHD in Shijiazhuang,and provides a strong basis and help for further diagnosis,prenatal diagnosis,treatment and genetic counseling of PAHD.