IB Biotech, Avda. Albufereta, 31, 03016 Alicante, Spain.
Hum Reprod. 2010 Jul;25(7):1843-8. doi: 10.1093/humrep/deq111. Epub 2010 May 28.
Human translocation carriers may present alterations in meiosis. Understanding the mechanism of meiotic segregation of reciprocal translocations is important for estimation of the risk of either pregnancy loss or birth defects. The objective of this work was to estimate meiotic segregation rates in preimplantation embryos from preimplantation genetic diagnosis (PGD) cycles of female and male reciprocal translocation carriers.
In 20 cycles for 14 couples, PGD was performed on 118 day three embryos using fluorescence in situ hybridization (FISH) with specific probes for each translocation. The meiotic segregation modes and the effect of the paternal origin of translocated carrier were estimated.
Overall, the proportions of alternate segregation for normal or balanced chromosome contents in preimplantation embryos from PGD cycles in reciprocal male and female carriers were not significantly different (35.5 versus 23.8%). However, the frequencies of adjacent-1 and adjacent-2 segregation were lower in embryos from female reciprocal translocation carriers than from male carriers. For male translocations, alternate segregation was the most frequent mode. The proportion of 3:1 segregation was the most frequent in female translocations carriers.
We report differences in segregation modes in embryos obtained from PGD cycles according to the gender of reciprocal translocation carrier. However, these differences did not affect the proportion of balanced embryos and the take home baby rate. The analysis of the meiotic behaviour of chromosomes and the differences between the meiotic products of female and male for a chromosomal rearrangement could help predict the outcome of PGD for translocation carriers.
人类易位携带者可能会出现减数分裂异常。了解相互易位减数分裂分离的机制对于评估妊娠丢失或出生缺陷的风险非常重要。本研究的目的是评估女性和男性相互易位携带者的胚胎植入前遗传学诊断（PGD）周期中胚胎减数分裂分离率。
在 14 对夫妇的 20 个周期中，使用针对每个易位的特异性探针，通过荧光原位杂交（FISH）对 118 个第三天的胚胎进行 PGD。估计减数分裂分离模式和易位携带者父源的影响。
总体而言，来自男性和女性相互易位携带者 PGD 周期的胚胎中，正常或平衡染色体含量的交替分离比例无显著差异（35.5%对 23.8%）。然而，女性相互易位携带者胚胎的相邻-1 和相邻-2 分离频率低于男性携带者。对于男性易位，交替分离是最常见的模式。女性易位携带者中 3:1 分离比例最常见。
我们报告了根据相互易位携带者的性别，PGD 周期中胚胎分离模式的差异。然而，这些差异并未影响平衡胚胎的比例和携带婴儿回家的比率。分析染色体的减数分裂行为以及女性和男性染色体重排减数分裂产物之间的差异，可以帮助预测易位携带者的 PGD 结果。
