Harper Joyce C
Joyce Harper, Embryology, IVF and Reproductive Genetics Group, Institute for Women's Health, University College London, London, UK.
J Med Screen. 2018 Mar;25(1):1-5. doi: 10.1177/0969141317691797. Epub 2017 Jun 14.
Preimplantation genetic diagnosis was first successfully performed in 1989 as an alternative to prenatal diagnosis for couples at risk of transmitting a genetic or chromosomal abnormality, such as cystic fibrosis, to their child. From embryos generated in vitro, biopsied cells are genetically tested. From the mid-1990s, this technology has been employed as an embryo selection tool for patients undergoing in vitro fertilisation, screening as many chromosomes as possible, in the hope that selecting chromosomally normal embryos will lead to higher implantation and decreased miscarriage rates. This procedure, preimplantation genetic screening, was initially performed using fluorescent in situ hybridisation, but 11 randomised controlled trials of screening using this technique showed no improvement in in vitro fertilisation delivery rates. Progress in genetic testing has led to the introduction of array comparative genomic hybridisation, quantitative polymerase chain reaction, and next generation sequencing for preimplantation genetic screening, and three small randomised controlled trials of preimplantation genetic screening using these new techniques indicate a modest benefit. Other trials are still in progress but, regardless of their results, preimplantation genetic screening is now being offered globally. In the near future, it is likely that sequencing will be used to screen the full genetic code of the embryo.
植入前基因诊断于1989年首次成功实施，作为一种替代产前诊断的方法，为有将遗传或染色体异常（如囊性纤维化）传递给孩子风险的夫妇提供服务。从体外产生的胚胎中获取活检细胞进行基因检测。自20世纪90年代中期以来，这项技术已被用作体外受精患者的胚胎选择工具，尽可能多地筛查染色体，希望选择染色体正常的胚胎能提高着床率并降低流产率。这个过程，即植入前基因筛查，最初是使用荧光原位杂交技术进行的，但11项使用该技术进行筛查的随机对照试验表明，体外受精分娩率并无改善。基因检测技术的进步促使阵列比较基因组杂交、定量聚合酶链反应和下一代测序技术被引入用于植入前基因筛查，三项使用这些新技术进行植入前基因筛查的小型随机对照试验显示出一定益处。其他试验仍在进行中，但无论结果如何，植入前基因筛查目前已在全球范围内开展。在不久的将来，很可能会使用测序技术来筛查胚胎的完整遗传密码。
