Yang Yi, Yang Ming, Shao Minjie, Wang Nan, Yan Yifang, Zhu Xiaohui, Yan Liying, Qiao Jie, Yan Zhiqiang
State Key Laboratory of Female Fertility Promotion, Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China.
National Clinical Research Center for Obstetrics and Gynecology, Peking University Third Hospital), Beijing, 100191, China.
J Assist Reprod Genet. 2025 May 6. doi: 10.1007/s10815-025-03492-8.
To determine whether recombination occurring around the breakpoints of translocated chromosomes may affect the accuracy of the current linkage analysis-based diagnosis of reciprocal translocation (RT) embryos.
Here, we have selected 688 single sperm cells sampled from 14 RT carriers with signed informed consent before semen collection and systematically investigated their chromosomal segregation patterns and potential recombination of translocated chromosomes.
We found that 39.96% of sperm cells showed alternative segregation patterns to produce normal and chromosomally balanced sperm cells, while 39.01% presented with an adjacent-1 segregation pattern, and 16.06% presented with an adjacent-2 segregation pattern, and 4.59% presented with a 3:1 segregation pattern. Moreover, we discovered a previously unknown segregation pattern at 0.38% occurrence. Notably, of the 887 recombination events on RT-associated chromosomes identified, 18 recombination events were located within the range of 5 Mb around breakpoints, among which 10/18 (55.6%) were located within 1-3 Mb of the breakpoint.
Our study provides evidence for recombination within the 5 Mb region flanking the breakpoints of translocated chromosomes, and these results suggest a non-negligible risk in the accurate diagnosis of chromosomal translocation in embryos through current linkage analysis-based diagnostic methods.
确定易位染色体断点周围发生的重组是否会影响当前基于连锁分析的相互易位（RT）胚胎诊断的准确性。
在此，我们从14名RT携带者中选取了688个单精子细胞，这些携带者在精液采集前签署了知情同意书，并系统地研究了它们的染色体分离模式以及易位染色体的潜在重组情况。
我们发现39.96%的精子细胞表现出交替分离模式，以产生正常和染色体平衡的精子细胞，而39.01%呈现相邻-1分离模式，16.06%呈现相邻-2分离模式，4.59%呈现3:1分离模式。此外，我们发现了一种发生率为0.38%的先前未知的分离模式。值得注意的是，在鉴定出的与RT相关染色体上的887个重组事件中，有18个重组事件位于断点周围5 Mb范围内，其中10/18（55.6%）位于断点的1-3 Mb范围内。
我们的研究为易位染色体断点侧翼5 Mb区域内的重组提供了证据，这些结果表明，通过当前基于连锁分析的诊断方法准确诊断胚胎染色体易位存在不可忽视的风险。
