一例假双着丝粒染色体携带者的胚胎植入前遗传学检测  

Preimplantation genetic testing of a carrier with pseudodicentric chromosome

作　　者：郝冬梅 王喜良 陈霞慧 马向薇 于月新 HAO Dongmei;WANG Xiliang;CHEN Xiahui;MA Xiangwei;YU Yuexin(Department of Reproductive Medicine,General Hospital of Northern Theater Command of the People's Liberation Army,Shenyang,Liaoning 110003,China)

机构地区：[1]中国人民解放军北部战区总医院生殖医学科,辽宁沈阳110003

出　　处：《中国优生与遗传杂志》2022年第4期668-671,共4页Chinese Journal of Birth Health & Heredity

基　　金：辽宁省自然科学基金指导计划(20180551228);军队计生专业科研课题项目(16JS014,16JS015)。

摘　　要：目的探讨假双着丝粒染色体患者的生育风险及遗传干预策略。方法对1例假双着丝粒染色体携带者行胚胎植入前遗传学检测(PGT),移植染色体正常胚胎并分析孕中期羊水染色体核型。结果外周血染色体核型为45,XX,der(11)t(11;20)(q25;p13),-20。荧光原位杂交(FISH)显示11号染色体长臂末端与20号染色体短臂末端区域融合形成了一条假双着丝粒染色体,但无功能基因缺失,携带者表型仍正常,可是存在生育问题。PGT检测发现在6枚胚胎中,2枚染色体拷贝数无异常(1枚为携带者,1枚为染色体正常胚胎),1枚相关染色体异常,3枚新发染色体异常。该病人移植染色体正常胚胎后顺利妊娠,羊水染色体核型为46,XX。结论假双着丝粒染色体携带者通过胚胎植入前遗传学检测,成功生育染色体完全正常的后代。由于存在染色体相互效应,该类患者的配子中产生新发染色体异常的风险增加,所以此类患者不良妊娠风险高,遗传咨询时建议患者使用PGT技术助孕。Objective To explore the reproductive risk and genetic intervention strategy of a patient with pseudodicentric chromosome. Methods Preimplantation genetic testing(PGT) was performed to identify embryos with normal chromosome and carrier embryos. The embryo with normal chromosomes was transferred to the patient. The karyotype of amniotic fluid cells was analyzed for the prenatal diagnosis in the second trimester. Results The karyotype was 45,XX,der(11)t(11;20)(q25;p13),-20. Fluorescence in situ hybridization(FISH) analysis found that the long arm end of chromosome 11 was fused with the short arm end of chromosome 20 to form a pseudodicentric chromosome but with no functional gene deletion. Although the phenotype of the carrier was normal, there were fertility problems. PGT studies demonstrated that among the six detected embryos, two embryos were without copy number variation(one was carrier embryo and another was normal embryo), one embryo with related chromosomal abnormality and three embryos with de novo abnormality. After normal embryo transfer, successful pregnancy was achieved, and amniotic fluid chromosomal karyotype was 46,XX. Conclusion Pseudodicentric carriers can successfully have offspring with normal chromosome by PGT technique. Patients with pseudodicentric chromosome can have the increased risk of de novo chromosome abnormalities as the result of the interchromosomal effect. PGT could be recommended during their genetic counseling due to the high risk of abnormal pregnancy.

关 键 词：假双着丝粒染色体 胚胎植入前遗传学检测 染色体相互效应 

分 类 号：R714.8[医药卫生—妇产科学]