21号环状染色体嵌合体胎儿临床表型和遗传学分析1例  

Clinical phenotype and genetic analysis of a fetus with ring chromosome 21 chimerism

作　　者：陶靖[1] 王诗瑞 鲁婷[1] 侯菲[1] 金华[1] Tao Jing;Wang Shirui;Lu Ting;Hou Fei;Jin Hua(Prenatal Diagnosis Center Jinan Maternal and Child Health Care Hospital,Jinan 250001,China)

机构地区：[1]济南市妇幼保健院产前诊断中心,济南250001

出　　处：《国际遗传学杂志》2024年第5期376-380,共5页International Journal of Genetics

基　　金：济南市科技局立项课题(202328018,202225064)。

摘　　要：目的对1例因B超提示胎儿唇裂并腭裂,胎儿腰椎半椎体的孕妇行介入性产前诊断,探索胎儿异常临床表型发生的原因及遗传特征。方法对该孕妇行羊膜腔穿刺手术,应用G显带法对胎儿羊水细胞染色体核型进行分析,临床全外显子测序(medical exome sequencing,MES)对胎儿羊水细胞及孕妇夫妻双方进行遗传学检测。结果胎儿染色体核型结果为46,XN,r(21)(p13q22.2)[83]/45,XN,-21[18],MES检测结果提示胎儿染色体21q22.2-q22.3区存在7.43 Mb片段的缺失,该孕妇夫妻双方的核型正常且未检出与子代遗传性疾病相关的罕见变异。结论胎儿唇裂并腭裂表型与染色体21q22.2-q22.3区片段缺失相关。染色体核型分析与MES检测的联合对环状染色体嵌合体相关的产前诊断和遗传咨询更加准确全面。Objective To perform an interventional prenatal diagnosis in a case due to ultrasound suggestive of fetal cleft lip with cleft palate and fetal lumbar hemivertebra,we explored the reasons for the occurrence of abnormal clinical phenotypes and genetic characteristics of the fetus.Methods Amniocentesis was performed in this pregnant woman,and the chromosomal karyotype of fetal amniotic fluid cells was analyzed by the G-banding method,and the genetics of fetal amniotic fluid cells and pregnant couples were examined by medical exome sequencing(MES).Results Chromosomal karyotyping was 46,XN,r(21)(p13q22.2)[83]/45,XN,-21[18],which indicated that there was a deletion of 7.43 Mb in the region of fetal chromosome 21q22.2-q22.3,and the karyotypes of the couple in this pregnant woman were normal,and there were no rare mutations associated with hereditary diseases in the offspring.Conclusion The phenotype of fetal cleft lip and cleft palate was associated with the deletion of a fragment of chromosome 21q22.2-q22.3 region.The combination of karyotyping and MES testing is more accurate and comprehensive for prenatal diagnosis and genetic counseling related to ring chromosome chimerism.

关 键 词：环状染色体 临床全外显子测序 核型分析 产前诊断 21q22.2-q22.3缺失 

分 类 号：R714.5[医药卫生—妇产科学]