脊髓肌萎缩症产前分子筛查临床应用并策略分析  

Clinical application and strategy analysis of prenatal molecular screening in spinal muscular atrophy

作　　者：刘春苗 孙东兰[2] 于湄[2] 张静[2] 杨玉秀[2] 孟雁欣 LIU Chun-miao;SUN Dong-lan;YU Mei;ZHANG Jing;YANG Yu-xiu;MENG Yan-xin(The First Department of Obstetrics, the Fourth Hospital of Shijiazhuang, Hebei Province, Shijiazhuang 050011, China;Prenatal Diagnosis Center, the Fourth Hospital of Shijiazhuang, Hebei Province, Shijiazhuang 050011, China)

机构地区：[1]河北省石家庄市第四医院产一科,河北石家庄050011 [2]河北省石家庄市第四医院产前诊断中心,河北石家庄050011

出　　处：《河北医科大学学报》2021年第3期304-308,329,共6页Journal of Hebei Medical University

基　　金：河北省青年自然科学基金项目(H2017106030)。

摘　　要：目的探讨分子生物学技术在脊髓肌萎缩症(spinal muscular atrophy,SMA)产前筛查中的临床应用价值及产前诊断相关策略。方法分析产前诊断中心就诊4568例样本作为研究对象,应用变性高效液相色谱分析技术(denaturing high performance liquid chromatography,DHPLC)进行运动神经元生存基因(survival motor neuron,SMN1/SMN2)拷贝数变异检测,应用Sanger测序技术进行SMN点突变检测。结果①4568例样本中3例SMA患者,2例SMN1外显子7/8纯合缺失,父母双方验证SMN1外显子7/8杂合缺失,拷贝数“1”,典型SMA携带者;1例患者检测出SMN1外显子7/8杂合缺失,拷贝数“1”,同时检出SMN1点突变变异位点p.Q164X,临床诊断为“1+1型”SMA患者;②126例SMA携带者,携带率约1/36,84例携带者SMN1外显子7/8拷贝数“1”,31例携带者SMN1外显子7拷贝数“1”,11例携带者SMN1外显子8拷贝数“1”;③明确SMA先证者、携带者基因型基础上,对25对夫妇双方均为携带者胎儿孕18周行羊水穿刺行SMA产前诊断,3例胎儿SMN1外显子7/8纯合缺失(SMA患者);1例胎儿SMN1外显子7/8杂合缺失(SMA携带者)。余胎儿检测未见SMN1拷贝数异常。Sanger测序1例胎儿携带p.Q164X点突变变异位点,余样本未见SMN异常。结论研究应用DHPLC联合点突变测序检测SMA携带发病检测,充分证实检测手段在SMA等遗传性疾病检测中的重要价值;新报SMN致病突变位点p.Q164X,丰富中国人群SMA致病基因数据库;该数据获得河北地区人群SMN1拷贝数分布及发病频率数据,对监测、指导及防控中国人群SMA发病及产前诊断有重要价值。单基因疾病携带者筛查是产前诊断基础,明确携带者变异类型及可能致病位点,选择准确分子手段靶向进行产前诊断胎儿发病检测,减少家庭及社会经济负担同时减少患者及家属的心理负担。Objective To investigate the clinical value of molecular biology in prenatal screening of spinal muscular atrophy(SMA)and its related strategies.Methods A total of 4568 samples of patients that presented to prenatal diagnosis center of our hospital were collected as the research subjects.The denaturing high performance liquid chromate graphy(DHPLC)was used to detect copy number variation of survival motor neuron(SMN1/SMN2),and Sanger sequencing technique was used to detect SMN point mutation.Results Of 3 SMA patients in 4568 samples,there were 2 with homozygous deletion of SMN1 exon 7/8.Both parents were verified as typical SMA carriers,carrying aheterozygous deletion of one copy of SMN1 exon 7/8.Another patient was clinically diagnosed as“type 1+1”SMA patient carrying aheterozygous deletion of one copy of SMN1 exon 7/8,and point mutation site in SMN1 p.Q164X.2.There were 126 SMA carriers,with a carrying rate of approximately 1/36;84 carriers with one copy of SMN1 exon 7/8;31 carriers with one copy of SMN1 exon 7,and 11 carriers with one copy of SMN1 exon 8.3.On the basis of identifying the SMA proband and carrier genotype,we performed SMA prenatal diagnosis of amniotic fluid puncture on both 25 couples who were carriers at 18 weeks of pregnancy,including 3 fetus carrying a homozygous deletion of SMN1 exon 7/8(SMA patient),and 1 fetus carrying aheterozygous deletion of SMN1 exon 7/8(SMA carrier).There was no abnormal SMN1 copy number in the remaining fetuses.Sanger sequencing 1 fetal carrying p.Q164x point mutation site,while the remaining samples had no abnormal SMN copy number.Conclusion DHPLC combined point mutation sequencing was used to detect the pathogenesis of SMA,which fully confirmed their significant value in the detection of genetic diseases such as SMA.The newly reported SMN mutation site of pathogenic gene p.Q164X enriched the database of SMA pathogenic genes in Chinese population.Carrier screening for single-gene disorder is the basis of prenatal diagnosis,which can identify the types of varian

关 键 词：高效液相色谱技术 Sanger测序 脊髓肌萎缩症 产前诊断 SMN1 

分 类 号：R715.5[医药卫生—妇产科学]