联合应用微阵列和目标基因捕获测序技术对不明原因智力障碍或发育迟缓患儿的诊断价值  

Application of single nucleotide polymorphism-microarray and target gene sequencing in the study of genetic etiology of children with unexplained intellectual disability or developmental delay

作　　者：高志杰[1] 姜茜[2] 程大志[1] 闫秀贤[1] 陈倩[1] 许克铭[1] 

机构地区：[1]首都儿科研究所附属儿童医院神经内科,北京100020 [2]首都儿科研究所遗传研究室儿童发育营养组学北京市重点实验室

出　　处：《中华儿科杂志》2016年第10期740-745,共6页Chinese Journal of Pediatrics

基　　金：首都儿科研究所青年基金（QN-2016-03）

摘　　要：目的 探讨单核苷酸多态性（SNP）微阵列和目标基因捕获测序技术在智力障碍或发育迟缓临床分子遗传学诊断中的应用价值.方法 前瞻性收集来自首都儿科研究所附属儿童医院神经内科门诊2015年9月至2016年2月就诊的智力障碍或发育迟缓患儿,对0-6岁及6-17岁患儿分别采用0-4岁小儿发育诊断量表和中国修订韦氏儿童智力量表进行智力评定,发育商低于49分或智商低于51分者纳入研究,采用SNP微阵列和目标基因捕获测序技术对智力障碍或发育迟缓患儿进行全基因组拷贝数变异（CNV）及致病基因变异分析,对检测的CNV采用定量PCR方法进行先证者及父母验证,对明确或疑似致病性基因变异采用Sanger测序方法进行验证及父母传递分析.结果 共纳入15例智力障碍或发育迟缓患儿,其中男9例、女6例,年龄7个月至16岁9个月,进行SNP微阵列检测后发现2例存在微缺失,分别涉及11q24.1q25和21q22.2q22.3区域,且均为新生变异,经Decipher数据库查询,上述变异均与智力障碍或发育迟缓相关;13例SNP微阵列检测结果为阴性的患儿,经目标基因捕获高通量测序、基因变异-临床表型关联分析及遗传学分析,确诊5例患儿为单基因病,2例为疑似,6例阴性.结论 通过微阵列技术联合目标基因捕获测序技术,可以明显提高不明原因智力障碍或发育迟缓患儿的分子遗传学病因诊断率.这两种技术的联合使用在智力障碍或发育迟缓的病因诊断中具有重要的临床意义.Objective To evaluate the application of single nucleotide polymorphism （SNP）-microarray and target gene sequencing technology in the clinical molecular genetic diagnosis of unexplained intellectual disability（ID） or developmental delay （DD）.Method Patients with ID or DD were recruited in the Department of Neurology,Affiliated Children＇s Hospital of Capital Institute of Pediatrics between September 2015 and February 2016.The intellectual assessment of the patients was performed using 0-6-year-old pediatric examination table of neuropsychological development or Wechsler intelligence scale （〉6 years）.Patients with a DQ less than 49 or IQ less than 51 were included in this study.The patients were scanned by SNP-array for detection of genomic copy number variations （CNV）,and the revealed genomic imbalance was confirmed by quantitative real time-PCR.Candidate gene mutation screening was carried out by target gene sequencing technology.Causal mutations or likely pathogenic variants were verified by polymerase chain reaction and direct sequencing.Result There were 15 children with ID or DD enrolled,9 males and 6 fcmales.The age of these patients was 7 months-16 years and 9 months.SNP-array revealed that two of the 15 patients had genomic CNV.Both CNV were de novo micro deletions,one involved 11q24.1q25 and the other micro deletion located on 21q22.2q22.3.Both micro deletions were proved to have a clinical significance due to their association with ID,brain DD,unusual faces etc.by querying Decipher database.Thirteen patients with negative findings in SNP-array were consequently examined with target gene sequencing technology,genotype-phenotype correlation analysis and genetic analysis.Five patients were diagnosed with monogenic disorder,two were diagnosed with suspected genetic disorder and six were still negative.Conclusion Sequential use of SNP-array and target gene sequencing technology can significantly increase the molecular genetic etiologic diagnosis rate of the patients with unexplained ID

关 键 词：发育障碍 DNA拷贝数异常 突变 靶向捕获二代测序技术 

分 类 号：R749.94[医药卫生—神经病学与精神病学]