摘要
目的:对一例无创产前检测(NIPT)中检出的21三体高风险病例进行产前诊断,明确其遗传学异常,为遗传咨询提供参考。方法:应用染色体G显带技术进行核型分析、多重荧光定量聚合酶链反应(QF⁃PCR)和单核苷酸多态性微阵列芯片(SNP⁃array)技术检测额外小标记染色体(sSMC)的来源和成分。结果:胎儿染色体核型为47,XN,+mar1[86]/48,XN,+mar1,+mar2[14],为新发变异。QF⁃PCR提示胎儿21号染色体的5个STR位点存在拷贝数异常,即21q21.1q22.11区域的D21S11、D21S1437和D21S2039存在嵌合三体,21q22.2q22.3区域的D21S1412和D21S1411存在三体型。SNP⁃array的检测结果为arr[GRCh37]21q11.2q22.2(15016487_40158518)×2⁃3(嵌合比例约35%),21q22.2q22.3(40174787_48093361)×3。结论:在产前诊断中应该联合应用多种检测手段,取长补短,才能更准确地进行诊断。
Objective:To present the prenatal diagnosis of a high⁃risk case of trisomy 21 detected in noninvasive prenatal testing(NIPT),clarify its genetic abnormalities,and provide reference for genetic counseling.Methods:Chromosome G⁃banding techniques were used for karyotype analysis.Multiplex fluorescent quantitative polymerase chain reaction(QF⁃PCR)and single nucleotide polymorphism microarray(SNP⁃array)were used to trace the source of small supernumerary marker chromosomes(sSMC)and components.Results:The karyotype of the fetal chromosome was 47,XN,+mar1[86]/48,XN,+mar1,+mar2[14],suggesting a de novo variation.QF⁃PCR showed abnormalities in copy number at five STR loci of the fetal chromosome 21,namely,chimeric trisomy at D21S11,D21S1437 and D21S2039 of 21q21.1q22.11,and trisomy at D21S1412 and D21S1411 of 21q22.2q22.3.The detection result of SNP array was arr[GRCh37]21q11.2q22.2(15016487_40158518)×2⁃3(about 35%of chimeric ratio)and 21q22.2q22.3(40174787_48093361)×3.Conclusion:In prenatal diagnosis,combined use of multiple detections should be useful in determining a more accurate diagnosis.
作者
黄霜
陈芳
陈素琴
Huang Shuang;Chen Fang;Chen Suqin(Department of Laboratory Medicine,Panyu District Hexian Memorial Hospital,Guangzhou 511400;Department of Genetics and Cell Biology,Zhongshan Medical College,Sun Yat-sen University,Guangzhou 510080,China)
出处
《广州医科大学学报》
2021年第6期26-30,共5页
Academic Journal of Guangzhou Medical University
基金
番禺区科技计划项目(2017⁃Z04⁃75)。
关键词
无创产前检测
染色体核型
单核苷酸多态性微阵列芯片
额外小标记染色体
Noninvasive prenatal testing(NIPT)
Chromosome karyotype
Single nucleotide polymorphism microarray(SNP array)
Small supernumerary marker chromosome(sSMC)