一例罗伯逊易位携带者的胚胎植入前遗传学诊断

目的　探讨植入前遗传学诊断 (preimplantation genetic diagnosis,PGD)用于筛选罗伯逊易位携带者无遗传缺陷后代的可行性及风险。方法　 1对因男方携带易位 (13;14 )染色体并伴少、弱精的原发不孕夫妇 ,经激素超促排卵和单精子卵胞浆内注射 (intracytoplasmic sperm injection,ICSI)进行体外受精(in vitro fertilization,IVF) ,当胚胎发育到 6～ 8细胞阶段 (受精后第 3天 )时 ,用酸化法活检 ,从每个胚胎中取出单个分裂球 ,用 L SI 13q和 Tel 14 q探针进行荧光原位杂交 (fluorescence in situ hybridization,FISH)检测 ,继续培养活检后的胚胎到第 2天 ,并选择正常胚胎移植 ,获临床妊娠后 ,于妊娠中期行羊水细胞染色体检查。结果　活检 10个胚胎 ,获得 8个 FISH诊断结果 :5 0 % (4/8)正常或平衡的胚胎 ,37.5 % (3/8)不平衡的胚胎 ,12 .5 % (1/8)不确定。将诊断正常或平衡的胚胎 3枚于活检第 2天移植入母体宫腔 ,获临床单胎妊娠 ,产前诊断证实胎儿核型为 4 6 ,XY,完全正常 ,现分娩一正常男婴。结论　需行辅助生殖技术治疗的患者 ,当携带有罗伯逊易位时 ,PGD用于筛除异常胚胎 ,解决患者的生育障碍、预防严重遗传病胎儿的产生具有重要价值。

Preimplantation genetic diagnosis for a patient with Robertsonian translocation

Objective To investigate the feasibility and risk of preimplantation genetic diagnosis (PGD) for screening normal offspring of Robertsonian translocation carriers. Methods This case was clinically diagnosed as primary infertility for 6 years; the husband was found to have chromosome der(13;14)(q10;q10) and oligozoospermia. For the solution of the couple's problem, controlled ovarian hyperstimulation(COH) and intracytoplasmic sperm injection(ICSI) were performed to obtain embryos. The embryos were drilled in zona by acidified Tyrode's solution at 6-8 cell stage(day 3 post-fertilization) and a single blastomere was removed from each embryo. All blastomeres were analyzed by fluorescence in situ hybridization(FISH) using the double color probes LSI 13q labeled by SpectrumOrange and Tel 14q labeled by SpectrumGreen. The embryos biopsied were cultured at once and the normal ones selected were transferred the next day. Prenatal diagnostic techniques were used to detect the karyotype of fetus at 18 weeks of gestation. Results Unbalanced, normal or balanced, and unclear embryos were separated. The couple obtained 50%(4/8)normal or balanced, and 37.5%(3/8)unbalanced, and 12.5%(1/8)unclear embryos. A singleton pregnancy followed, and the karyotype of the fetus (46,XY) was detected by prenatal diagnostic techniques. Conclusion PGD is useful for screening out unbalanced embryos and is very valuable for solving the reproductive problem of Robertsonian translocation carriers and for avoiding fetal beings with severe disorders.