一例母系嵌合的Nicolaides-Baraitser综合征患儿的临床特征及基因变异分析  

Analysis of clinical characteristics and genetic variant in a child with Nicolaides-Baraitser syndrome due to maternal mosaicism

作　　者：刘晓 杨秋萍 石聪聪[1] 郝虎[1] 肖昕[1] 李思涛[1] Liu Xiao;Yang Qiuping;Shi Congcong;Hao Hu;Xiao Xin;Li Sitao(Department of Pediatrics,The Sixth Affiliated Hospital,Sun Yat-sen University,Guangzhou,Guangdong 510655,China)

机构地区：[1]中山大学附属第六医院儿科,广州510655

出　　处：《中华医学遗传学杂志》2022年第12期1366-1369,共4页Chinese Journal of Medical Genetics

基　　金：广东省科技计划(2020A1414010111)。

摘　　要：目的:探讨1例表现为全面发育迟缓、肝功能异常、先天性心脏病、大脑畸形的患儿的基因检测结果,并分析候选变异的致病性。方法:采集患儿及父母外周血标本,提取基因组DNA,进行全外显子组高通量测序,对候选变异进行Sanger测序验证及生物信息学分析。结果:基因检测结果提示患儿SMARCA2基因存在c.2002G>T(p.Glu668Ter)杂合变异,生物信息学分析提示可能致病变异,患儿母亲的外周血基因组DNA中,检测到低比例的嵌合变异,高精度定点检测示变异比例为0.054(246/4549)。结论:该患者被诊断为SMARCA2基因变异引起的Nicolaides-Baraitser综合征,其母存在低比例的嵌合变异。Objective To carry out genetic testing for a child featuring global developmental delay,abnormal liver function,congenital heart disease,and brain malformation.Methods Peripheral blood samples of the child and his parents were collected for the extraction of genomic DNA and trio-whole exome sequencing.Candidate variant was verified by Sanger sequencing.Results Genetic testing revealed that the child has harbored a heterozygous c.2002G>T(p.Glu668Ter)variant of the SMARCA2 gene,which was predicted to be likely pathogenic by bioinformatic analysis.His mother was found to be a low-percentage mosaic for the same variant,with a ratio of 0.054(246/4549).Conclusion The child was diagnosed with Nicolaides-Baraitser syndrome resulting from maternal mosaicism for the SMARCA2 gene variant.

关 键 词：Nicolaides-Baraitser综合征 SMARCA2基因 基因检测 

分 类 号：R725.9[医药卫生—儿科] R440[医药卫生—临床医学]