一例罕见7q11.23重复综合征的产前诊断

摘要

目的 联合应用多种技术产前检测7q11.23重复综合征1例.方法 采集1例孕中期胎儿的羊水及其父母的外周血样本,行染色体G显带分析,提取羊水DNA进行BoBs分析,同时用单核苷酸多态性微阵列芯片(single nucleotide polymorphism array,SNP array)进行全基因组拷贝数变异分析,最后用荧光原位杂交技术(fluorescence in situ hybridization,FISH)进行确诊.结果 胎儿羊水细胞染色体G显带核型及父母染色体核型未见异常;BoBs分析检出胎儿7q11.23区存在重复;SNP-array Affymetrix CytoScan 750K Array基因芯片分析结果显示胎儿染色体7q11.23区存在1.5 Mb片段的重复;FISH检测确认胎儿为nuc ish 7q11.23(ELNX 3).结论 通过结合BoBs分析、SNP array以及FISH,产前诊断1例7q11.23重复综合征胎儿.%Objective To explore the application of combined techniques for the prenatal diagnosis of a case with 7q11.23 duplication.Methods Amniocentesis was performed in the second trimester for a mother with a high risk suggested by serological prenatal screening.G-banded chromosomal analysis was performed on cultured amniocytes and peripheral blood samples from both parents.DNA from amniotic fluid sample was isolated for a BACs-on-Beads (BoBs) assay.To define the range of duplication,copy number variation was determined with single nucleotide polymorphism array (SNP array,Affymetrix CytoScan 750K) and fluorescence in situ hybridization (FISH) analysis.Results Chromosomal analysis suggested that the fetus and both parents all had a normal karyotype,while a duplication of 7q11.23 was detected by the BoBs assay.SNP array revealed a 1.5 Mb duplication in chromosome 7q1 1.23,which was confirmed by FISH.Conclusion Combined prenatal BoBs,SNP array and FISH has enabled effective diagnose of a case with 7q11.23 syndrome.