BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included....BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.展开更多
目的对1个孕中期反复出现结构异常胎儿的家系进行遗传学分析,明确导致胎儿发育异常的可能原因,为该家系的遗传咨询和产前诊断提供依据。方法,应用染色体G显带、拷贝数变异测序(copy number variation-sequencing,CNV-seq)及荧光原位杂交...目的对1个孕中期反复出现结构异常胎儿的家系进行遗传学分析,明确导致胎儿发育异常的可能原因,为该家系的遗传咨询和产前诊断提供依据。方法,应用染色体G显带、拷贝数变异测序(copy number variation-sequencing,CNV-seq)及荧光原位杂交(fluorescence in situ hybridization,FISH)技术对胎儿组织及父母的外周血染色体进行分析鉴定。结果CNV-seq结果显示胎儿基因组存在一段6.59Mb重复(7p22.3-p22.1)与一段3.81 Mb缺失(4p16.3);父母G显带核型未见明显异常;FISH结果显示父亲4号染色体短臂末端与7号染色体短臂末端存在微小片段的相互易位。结论7p微重复与4p微缺失可能是导致该家系胎儿发育异常的原因。这些染色体组的微小结构畸变源于父亲存在的隐匿染色体平衡易位。在常规染色体检查无特殊且反复出现不良妊娠的夫妻中,应该考虑到亚显微染色体相互易位的可能,并经FISH等检测技术予以确认。展开更多
文摘BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.
文摘目的对1个孕中期反复出现结构异常胎儿的家系进行遗传学分析,明确导致胎儿发育异常的可能原因,为该家系的遗传咨询和产前诊断提供依据。方法,应用染色体G显带、拷贝数变异测序(copy number variation-sequencing,CNV-seq)及荧光原位杂交(fluorescence in situ hybridization,FISH)技术对胎儿组织及父母的外周血染色体进行分析鉴定。结果CNV-seq结果显示胎儿基因组存在一段6.59Mb重复(7p22.3-p22.1)与一段3.81 Mb缺失(4p16.3);父母G显带核型未见明显异常;FISH结果显示父亲4号染色体短臂末端与7号染色体短臂末端存在微小片段的相互易位。结论7p微重复与4p微缺失可能是导致该家系胎儿发育异常的原因。这些染色体组的微小结构畸变源于父亲存在的隐匿染色体平衡易位。在常规染色体检查无特殊且反复出现不良妊娠的夫妻中,应该考虑到亚显微染色体相互易位的可能,并经FISH等检测技术予以确认。
