45,X/46,X,idic(Y)(q11.2)嵌合体1例胎儿的遗传学分析  

Genetic analysis of a fetus with with 45,X/46,X,idic(Y)(q11.2)mosaicism

作　　者：潘飞燕[1] 张蔚卿 章卫国[1] Pan Feiyan;Zhang Weiqing;Zhang Weiguo(Central Laboratory,Taizhou Hospital,Linhai,Zhejiang 317000,China;Department of Obstetrics and Gynecology,Taizhou Hospital,Linhai,Zhejiang 317000,China)

机构地区：[1]台州医院中心实验室,临海317000 [2]台州医院妇产科,临海317000

出　　处：《中华医学遗传学杂志》2024年第8期897-902,共6页Chinese Journal of Medical Genetics

基　　金：浙江省医药卫生科技计划(2021KY1196);台州市科技计划(20ywa13);恩泽医疗中心(集团)科学研究基金(17EZB4)。

摘　　要：目的探讨1例胎龄25^(+)周无创产前筛查(NIPT)提示为性染色体可能异常的胎儿的遗传学特征。方法选取2023年1月6日就诊于台州医院不孕与优生门诊的1例无创产前检测结果异常的胎儿作为研究对象,回顾性分析相关临床资料。应用NIPT、染色体核型分析、染色体拷贝数变异测序(CNV-seq)、荧光原位杂交(FISH)和多重PCR检测对胎儿进行遗传学分析。结果孕妇孕30^(+)周的NIPT检测为X染色体单体,胎儿G显带染色体核型为45,X[59]/46,X,del(Y)(q11.2)[17],CNV-seq提示Y染色体q11.222q12区存在7.98 Mb的拷贝数缺失,p11.31q11.221区存在16.92 Mb的嵌合性拷贝数缺失,FISH提示胎儿为嵌合体型性染色体异常,且含有2个SRY基因,多重PCR检测显示AZF b+c区完全缺失,C显带显示Y染色体两端均可见一深染致密着丝粒。胎儿的染色体核型最终被确定为45,X/46,X,idic(Y)(q11.2)嵌合体。胎盘组织CNV-seq结果与NIPT一致,胎儿组织CNV-seq结果证实为45,X/46,XY嵌合体。夫妻双方外周血CNV-seq检测未见明显异常。结论联合NIPT、染色体核型分析、CNV-seq、FISH和多重PCR检测技术诊断该胎儿核型为45,X/46,X,idic(Y)(q11.2)嵌合体伴AZF b+c区缺失,为该孕妇夫妇提供了产前诊断依据。ObjectiveTo explore the genetic characteristics of a fetus with sex chromosome abnormality indicated by non-invasive prenatal testing(NIPT)at 25+gestational weeks.MethodsA pregnant woman who was admitted to the Taizhou Hospital for abnormal NIPT result on January 6,2023 was selected as the study subject.Relevant clinical data was collected.The fetus was subjected to chromosomal karyotyping analysis,copy number variation sequencing(CNV-seq),fluorescence in situ hybridization(FISH),and multiplex PCR assays.ResultsNIPT had suggested monosomy of X chromosome.The fetus was found to have a chromosomal karyotype of 45,X[59]/46,X,del(Y)(q11.2)[17]at 30^(+)weeks of gestational age.CNV-seq suggested the presence a 7.98 Mb deletion at Yq11.222q12 and a mosaicism 16.92 Mb deletion.FISH suggested that the fetus harbored two SRY genes and a mosaicism sex chromosomal abnormality,and multiplex PCR revealed that its AZF b+c region was completely deleted.C-banded karyotyping showed darkly stained dense mitotic granules at both ends of the Y chromosome.The fetus was ultimately determined as a 45,X/46,X,idic(Y)(q11.2)mosaicism.Following elected abortion,testing of the fetal tissue confirmed the presence of 45,X/46,XY mosaicism,and CNV-seq result of the placental tissue was compatible with that of NIPT.CNV-seq analysis of the couple revealed no obvious abnormality.ConclusionWith combined NIPT,karyotyping,CNV-seq,FISH and multiplex PCR assays,the fetus was diagnosed as a 45,X/46,X,idic(Y)(q11.2)mosaicism with deletion of the AZF b+c region.Above finding has enabled prenatal diagnosis for the fetus.

关 键 词：产前诊断 45 X/46 XY嵌合体 AZF区微缺失 SRY基因 

分 类 号：R714.5[医药卫生—妇产科学]