9p重复伴8p末端缺失胎儿的遗传学分析并文献复习

Genetic study of a fetus with 9p duplication and 8p terminal deletion syndrome and literature review

目的对1例产前异常胎儿及其双亲行细胞遗传学及分子遗传学研究,以明确胎儿异常遗传物质的来源及其发生机制。探讨染色体微阵列分析(Chromosomal Microarray Analysis,CMA)在临床产前诊断中的临床价值。方法对患儿脐血及其双亲外周血进行常规G显带分析,进一步应用CMA对患儿进行全基因组拷贝数分析。结果 G显带核型分析提示胎儿脐血染色体核型结果为46,XX,der(8)(?::p23→qter),其母亲外周血核型结果为46,XX,t(8,9)(p23,p22),父亲核型未见异常。胎儿衍生8号染色体来源于携带平衡易位染色体的母亲。CMA检测提示胎儿存在9p21.3-p24.3区域22.666Mb的重复片段及8p23.2-p23.3末端4.413Mb的缺失片段。胎儿核型最终修正确定为46,XX,der(8)t(8,9)(p23.2,p21.3)mat。结论胎儿染色体9p重复伴8p末端缺失可能造成出生后的严重异常表型,本文对该患胎进行了产前诊断及遗传学分析,为临床产前诊断和遗传咨询提供了有力依据。

Objective:Study of a abnormality fetus and its family by cytogenetics and molecular genetics.Explore the clinical value of Chromosomal Microarray Analysis(CMA)in prenatal diagnosis.Methods:G-banding analysis was performed on the umbilical cord blood of the fetus and peripheral blood of its parents,and further genome-wide copy number analysis was performed using CMA.Results:G banding karyotype analysis result of fetal is 46,XX,der(8)(?::p23→qter),its mother result is 46,XX,t(8,9)(p23,p22).CMA detection indicated the fetal with a 22.666 Mb duplication in the 9 p21.3-p24.3 region and4.413 Mb of deletion at the end of 8 p23.2-p23.3.The final karyotype analysis result of fetal is 46,XX,der(8)t(8,9)(p23.2,p21.3)mat.Conclution:Fetal chromosome 9 p duplication with 8 p terminal deletion may result in severe abnormal phenotypes after birth.In this paper,prenatal diagnosis and genetic analysis of the fetus were carried out,which provided a strong basis for clinical prenatal diagnosis and genetic counseling.