Benadiva C A, Kligman I, Munné S
The Center for Reproductive Medicine and Infertility, Department of Obstetrics and Gynecology, The New York Hospital-Cornell Medical Center, New York, USA.
Fertil Steril. 1996 Aug;66(2):248-55.
To determine aneuploidy for chromosome 16 by recycling nuclei of cells already analyzed for chromosomes X, Y, 18, 13, and 21 using multiple fluorescence in situ hybridization in preimplantation human embryos in a time frame compatible with clinical IVF and to asssess the incidence of chromosome 16 aneuploidy in embryos related to maternal age.
Prospective experimental study.
In vitro fertilization program in a tertiary center.
One hundred four consenting patients undergoing IVF.
Chromosome 16 ploidy was analyzed in a total of 195 embryos. In 89 embryos, a standard multiple-probe fluorescence in situ hybridization was used for chromosomes X, Y, 18 and 16 (series 1). The remaining 106 embryos (series 2) were reanalyzed with a new procedure for chromosome 16, which involves rehybridization with a digoxigenin-labeled alpha satellite probe after the standard analysis for chromosomes X, Y, 18, 13, and 21 was completed. The embryos were assigned to one of three groups according to the women's age; group 1: </= 34 years (n = 34), group 2: 35 to 39 years (n = 47); group 3: >/= 40 years (n = 23).
Successful analysis, including biopsy, fixation, and fluorescence in situ hybridization was achieved in 86% of the blastomeres within approximately 10 hours. A significant relationship was found between the rate of aneuploidy for chromosome 16 and increasing maternal age: group 1: 0%, group 2: 6.3%, and group 3: 11.7%. Monosomy for chromosome 16 was found in 72.7% of the 11 embryos carrying chromosome 16 anomalies, with the remaining three embryos having two trisomies and one tetrasomy. This new protocol was applied clinically to five patients undergoing preimplantation aneuploidy assessment. Aneuploidy for chromosome 16 was found in five embryos from three of those patients.
This study demonstrates that preimplantation genetic diagnosis of the major human aneuploidies is achievable within a time frame compatible with IVF. In addition, this study confirms, for embryos, the existing data from spontaneous abortions suggesting that chromosome 16 aneuploidy increases with maternal age. The high prevalence of embryonic monosomy, which is rarely found in spontaneous abortions, suggests that monosomy 16 could be a factor associated with failure of implantation, as well as pointing to a different mechanism involved in the generation of chromosome 16 aneuploidy.
通过对已进行X、Y、18、13和21号染色体分析的细胞进行核回收，利用多重荧光原位杂交技术，在与临床体外受精相适应的时间范围内，确定植入前人类胚胎中16号染色体的非整倍体情况，并评估与母亲年龄相关的胚胎中16号染色体非整倍体的发生率。
前瞻性实验研究。
三级中心的体外受精项目。
104名接受体外受精的自愿患者。
共对195个胚胎进行了16号染色体倍性分析。在89个胚胎中，使用标准的多探针荧光原位杂交技术对X、Y、18和16号染色体进行分析（系列1）。其余106个胚胎（系列2）在完成X、Y、18、13和21号染色体的标准分析后，采用一种新的16号染色体分析方法进行重新分析，该方法包括用洋地黄毒苷标记的α卫星探针进行再杂交。根据女性年龄将胚胎分为三组；第1组：≤34岁（n = 34），第2组：35至39岁（n = 47）；第3组：≥40岁（n = 23）。
在大约10小时内，86%的卵裂球成功完成了分析，包括活检、固定和荧光原位杂交。发现16号染色体非整倍体率与母亲年龄增加之间存在显著关系：第1组：0%，第2组：6.3%，第3组：11.7%。在11个携带16号染色体异常的胚胎中，72.7%为16号染色体单体，其余3个胚胎为两个三体和一个四体。该新方案已临床应用于5名接受植入前非整倍体评估的患者。在其中3名患者的5个胚胎中发现了16号染色体非整倍体。
本研究表明，在与体外受精相适应的时间范围内，可以实现对人类主要非整倍体的植入前基因诊断。此外，本研究证实了胚胎中来自自然流产的现有数据，表明16号染色体非整倍体随母亲年龄增加而增加。胚胎单体的高发生率在自然流产中很少见，这表明16号染色体单体可能是与植入失败相关的一个因素，也表明16号染色体非整倍体产生涉及不同的机制。
