产前诊断中出现额外小标记染色体的检测模式探讨及遗传咨询

Exploration of detection model of supernumerary small marker chromosome and genetic counseling in prenatal diagnosis

目的探讨产前诊断中出现额外小标记染色体(supernumerarysmallmarkerchromosome,sSMC)的检测模式及临床意义。方法选取来我院就诊的9044例孕妇进行胎儿染色体核型分析,对出现标记染色体的胎儿进行染色体微阵列分析(chromosomalmicroarrayanalysis,CMA)或高通量测序及父母染色体核型分析。结果分析9044例胎儿核型检出标记染色体7例,检出率0.077%,其中2例为遗传获得,1例为父亲平衡易位产生的衍生染色体,其余可能为新生突变。结论联合应用染色体核型分析、CMA或高通量测序、C、N带测定、荧光原位杂交技术(fluorescenceinsitu hybridization,FISH)检测判断标记染色体的遗传特性及来源,为遗传咨询提供参考。

Objective:To explore the detection pattern and clinical significance of supernumerary small marker chromosome in prenatal diagnosis.Methods:9044 pregnant women were selected for fetal karyotype analysis.Chromosome microarray analysis(CMA)or high-throughput sequencing and parent chromosome karyotype analysis were performed on fetuses with supernumerary small marker chromosome.Results:Seven of 9044 fetuses were found to have supernumerary small marker chromosome,with a detection rate of 0.077%.Two of them were inherited,one was derived from the father′s balanced translocation,and the others might be new mutations.Conclusion:The genetic characteristics and sources of marker chromosomes can be determined by combining chromosome karyotype analysis,CMA or high throughput sequencing,C,N banding and fluorescence in situ hybridization,which can provide reference for genetic counseling.