ASXL3基因新发变异致Bainbridge-Ropers综合征1例患儿的报告暨文献复习  

Report of a child with Bainbridge-Ropers syndrome due to a novel variant of ASXL3 gene and a literature review

作　　者：蒋云舒 李荣[1] 李晓南[1] Jiang Yunshu;Li Rong;Li Xiaonan(Department of Children′s Health,Nanjing Children′s Hospital,Nanjing,Jiangsu 210008,China)

机构地区：[1]南京市儿童医院儿童保健科,南京210008

出　　处：《中华医学遗传学杂志》2024年第8期966-972,共7页Chinese Journal of Medical Genetics

基　　金：江苏省医学会儿科医学科研专项资金(SYH-32034-0070)。

摘　　要：目的探讨1例Bainbridge-Ropers综合征(BRPS)患儿的临床特征与遗传学病因。方法以2019年6月26日于南京市儿童医院就诊的1例BRPS患儿作为研究对象。收集患儿的临床资料,抽取患儿及其父母的外周静脉血样,应用全外显子组测序(WES)对患儿进行基因检测,采用Sanger测序进行家系验证,并对候选变异进行生物信息学分析。结果患儿为6月龄女性,表现为特殊面容、喂养困难、营养不良、全面发育落后、肌张力低下、转氨酶轻度升高和腕关节尺偏。WES检测结果提示患儿携带ASXL3基因c.1533_1534delTT变异。经Sanger测序验证,患儿父母ASXL3基因均为野生型,提示患儿为新发变异。生物信息学分析:ASXL3基因c.1533_1534delTT变异在HGMD及ClinVar等数据库中未见收录;查询ExAC、1000 Genomes及gnomAD等数据库的亚洲正常人群中未收录携带者频率;根据美国医学遗传学与基因组学学会(ACMG)相关指南,该变异被评估为可能致病性(PVS1+PS2+PM2_Supporting)。结论ASXL3基因c.1533_1534delTT变异可能为上述BRPS患儿的遗传学病因。上述发现为患儿的临床诊断与遗传咨询提供了依据。ObjectiveTo explore the clinical phenotype and genetic basis of a child with Bainbridge-Ropers syndrome(BRPS).MethodsA child with BRPS who had visited Nanjing Children′s Hospital on June 26,2019 was selected as the study subject.Clinical data of the child was reviewed.Genomic DNA was extracted from peripheral blood samples of the child and her parents.Whole exome sequencing(WES)was carried out,and candidate variant was verified by Sanger sequencing and bioinformatic analysis.ResultsThe child was a 6-month-old girl with peculiar facial features,feeding difficulties,malnutrition,global developmental delay,hypotonia,mildly elevated aminotransferase and ulnar deviation.Results of WES showed that she has harbored a c.1533_1534del variant of the ASXL3 gene.Sanger sequencing confirmed that neither of her parents has carried the same variant.No similar case had been retrieved from the HGMD and ClinVar databases.No frequency for this variant among Asian populations was available in the ExAC,1000 Genomes,and gnomAD databases.Based on the guidelines from the American College of Medical Genetics and Genomics(ACMG),the c.1533_1534del variant of the ASXL3 gene was determined to be likely pathogenic(PVS1+PS2+PM2_Supporting).ConclusionThe ASXL3 gene c.1533_1534del variant probably underlay the BRPS in this child.Above finding has provided a reference for the clinical diagnosis and genetic counseling for children with similar disorders.

关 键 词：Bainbridge-Ropers综合征 ASXL3基因 全外显子组测序 全面性发育落后 特殊面容 

分 类 号：R725.9[医药卫生—儿科]