产前诊断1例胎儿嵌合型9号染色体部分三体的遗传学分析

Genetic analysis of chimeric trisomy in part of 9 chromosome of a fetal case that found in prenatal diagnosis

目的通过一例胎儿9号染色体部分嵌合重复的病例分析,探讨分子检测与核型分析在产前诊断中的应用,并分析重复片段可能出现的遗传学效应,提供遗传咨询。方法通过常规G显带核型分析和CNV-seq、CMA芯片技术对胎儿羊水细胞进行检测,结果进行分析比对。结果核型分析结果未见异常;CNV-seq检测结果提示9号染色体p13.1-q21.11存在大小约31.6Mb的嵌合重复,嵌合比例约为36%;CMA结果与CNV-seq结果一致。结论多种检测方法在产前诊断中联合应用,能够弥补单一检测方法的局限性而造成的漏诊和误诊,及时为产前咨询提供更加全面的实验室依据和更加全面的风险评估。

Objective By analyzing a case of mosaic duplication in part of 9 chromosome,to discuss the application of molecular detection and karyotype analysis in prenatal diagnosis.In addition,the possible genetic effects of the repeats were also analyzed and provide genetic couseling.Methods Using G-banding karyotype analysis,CNV-seq and CMA technology to detect the cells in fetal amniotic fluid,and the results were analyzed and compared.Results No abnormal was in the karyotype analysis.The results of CNV-Seq and CMA showed a 31.6Mb mosaic duplication in p13.1-q21 of number 9 chromosome.The chimerism ratio was about 36%.Conclusions The combination of multiple testing methods during prenatal diagnosis could avoid missed diagnosis and misdiagnosis due to boundedness of single use of test method,provide more comprehensive laboratory basis and more comprehensive risk assessment for prenatal consultation in a timely manner.