摘要
目的探讨对核型为49,XYYYY非嵌合体的超数Y染色体胎儿的产前诊断遗传咨询。方法患者孕18周,因血清学产前筛查为唐氏综合征高风险于2020年6月1日在云南省第一人民医院医学遗传科进行遗传咨询,知情同意后抽取胎儿羊水,应用G显带染色体核型分析技术和低覆盖度高通量测序技术对未经培养的羊水样本做拷贝数变异测序,进行遗传学分析和产前诊断。结果胎儿羊水细胞染色体核型为49,XYYYY,未经培养的胎儿羊水样本拷贝数变异测序结果为:seq[GRCh37](1-22)×2,(X)×1,(Y)×4,两种遗传学分析技术的检测结果均提示此胎儿为非嵌合体的4个Y染色体,即超数Y染色体。查询文献,全球共有6例49,XYYYY核型非嵌合体报道,其中5例为出生后患者,均有智力及语言发育障碍等较严重的临床表型。经产前诊断遗传咨询后,本例孕妇和家属自愿选择终止妊娠。结论超数Y染色体的49,XYYYY在胎儿期无超声可见的异常,但非嵌合体患者出生后可能出现智力和语言发育迟缓、特殊面容及骨骼发育异常等表型,可导致智力损害的严重出生缺陷,需在产前诊断遗传咨询中加以重视。
Objective To discuss the prenatal diagnosis and genetic consultation of non-mosaic super numeral Y chromosome fetus with 49,XYYYY karyotype.Methods The pregnant woman,who underwent amniocentesis at 18 weeks of gestation because of high risk of trisomy-21 in the serological prenatal screening,received genetic consultation in the Medical Genetics Department of Yunnan First People’s Hospital on June 1,2020.After informed consent,small amount of amniotic fluid that surrounds the fetus was removed.The uncultured sample of amniotic fluid underwent genetic analysis and prenatal diagnosis by both G-band karyotyping and low-coverage high-throughput sequencing.Results The karyotype of fetal amniotic fluid cells was 49,XYYYY,and the CNV-seq on uncultured amnio fluid sample showed the following result:seq[GRCh37](1-22)×2,(X)×1,and(Y)×4,and both genetic analysis techniques indicated that there were four copies of Y chromosome in this sample,that is,super numeral Y chromosome.Six cases of49,XYYYY non-chimera have been reported through consulting literature materials,and five of patients presented series clinical phenotypes such as mental retardation and language development delay.After clinical genetic counseling the patient and her family members chose to terminate the pregnancy.Conclusion Fetuses with super numeral Y chromosome 49,XYYYY may have no visible ultrasound abnormalities in trimesters,but most such patients may suffer from mental retardation,language development delay,special facial features,and bone developmental abnormalities.They are likely to suffer severe birth defects including mental impairment after birth.This issue should be paid more attention to in prenatal diagnosis and genetic counseling.
作者
来怡君
冯燕
银益飞
朱姝
王蕾
杨必成
李朋
赵庆芬
李海春
朱宝生
唐新华
LAI Yi-jun;FENG Yan;YIN Yi-fei;ZHU Shu;WANG Lei;YANG Bi-cheng;LI Peng;ZHAO Qing-fen;LI Hai-chun;ZHU Bao-sheng;TANG Xin-hua(The First People’s Hospital of Yunnan Province Affiliated to Kunming University of Science and Technology,Yunnan Provincial Clinical Research Center for Birth Defect and Rare Disease,Kunming 650011,China)
出处
《中国实用妇科与产科杂志》
CAS
CSCD
北大核心
2020年第9期874-877,共4页
Chinese Journal of Practical Gynecology and Obstetrics
基金
云南省卫生科技计划项目(2014NS281)
云南省重大科技专项(2019ZF015)。
