染色体易位的植入前遗传学诊断

目的 观察染色体平衡易位和罗伯逊(罗氏)易位基因携带者夫妇进行植入前遗传学诊断(PGD)后的胚胎染色体遗传特征和胚胎着床、妊娠情况,探讨PGD在染色体易位基因携带者夫妇实现正常生育中的意义.方法 用荧光原位杂交(FISH)技术对36对夫妇的胚胎进行PGD,其中14例为染色体平衡易位(平衡易位组),22例为染色体罗氏易位(罗氏易位组),并对诊断结果和胚胎着床、妊娠情况进行分析.结果 36例患者共活检胚胎253个,成功诊断胚胎225个,成功率为88.9%(225/253),获得可供移植的正常或平衡的胚胎共58个.平衡易位组和罗氏易位组PGD后胚胎着床率分别为36%(5/14)和14%(6/44),临床妊娠率分别为4/9和26%(5/19).结论 PGD可有效诊断胚胎染色体平衡易位和罗氏易位,避免反复流产和不必要的非意愿性终止妊娠,并获得理想的胚胎着床率和临床妊娠率.

Preimplantation genetic diagnosis of translocation

Objectives To observe the genetic characteristics of chromosomes and the rates of implantation and pregnancy in couples of translocation carriers who undergo preimplantation genetic diagnosis (PGD) and to evaluate the significance of PGD in the treatment of translocation carriers. Methods Fluorescence in situ hybridization (FISH) was performed to analyze the embryos of 12 carriers of reciprocal translocation and 22 carriers of Robertsonian translocation. The results of diagnosis and the implantation and pregnancy rates were analyzed. Results A total of 253 embryos from 36 couples were retrieved and FISH was applied for the examination. The characteristics of chromosomes were diagnosed in 225 embryos and the rate of successful PGD was 88.9%. Fifty-eight embryos were found to have normal chromosome or balanced translocation and were transferred into the uterus. The rate of implantation was 36% (5/14) and 14% (6/44) and the rate of pregnancy was 4/9 and 26% (5/19) for carriers of Robertsonian translocation and reciprocal translocation, respectively. Conclusions The FISH-based PGD is effective in the diagnosis of Robertsonian translocation and reciprocal translocation of embryos. It provides the possibility of a high rate of implantation and pregnancy, and avoids recurrent abortion and unwilling termination of pregnancy.