Reproductive Medical Center, First Affiliated Hospital of Zhengzhou University, No.1 Jianshe Road, Zhengzhou, China.
BMC Genomics. 2020 Apr 29;21(1):326. doi: 10.1186/s12864-020-6731-9.
Balanced complex chromosome rearrangements (BCCR) are balanced chromosomal structural aberrations that involve two or more chromosomes and at least three breakpoints. It is very rare in the population. The objective is to explore the difference of influence of three types of BCCR on early embryonic development and molecular karyotype.
Twelve couples were recruited including four couples of three-way rearrangements carriers (group A), three couples of double two-way translocations carriers (group B) and five couples of exceptional CCR carriers (group C). A total of 243 oocytes were retrievedin the seventeen preimplantation genetic testing (PGT) cycles, and 207 of these were available for fertilization. After intracytoplasmic sperm injection, 181oocytes normally fertilized. The rates of embryos forming on day3 in three groups were 87.88, 97.78 and77.14%, which was significantly different (P = 0.01). Compared with group B, the rate of embryo formation was statistically significantly lower in group C (P = 0.01). Furthermore, the rates of high-quality blastocysts in three group were 14.71, 48.15 and 62.96%, respectively, which was significantly different (P = 0.00). Compared with group B andC, the rate of high-quality blastocysts in group A was statistically significantly lower (P = 0.00;P = 0.00). Comprehensive chromosome analysis was performed on 83 embryos, including 75 trophectodermcellsand 8 blastomeres. Except 7 embryos failed to amplify, 9.01%embryos were diagnosed as euploidy, and 90.91% were diagnosed as abnormal. As for group A, the euploid embryo rate was 10.71%and the abnormal embryo rate was 89.29%. In group B,the euploid embryo rate was 3.85%, the abnormal embryo rate was 96.15%. The euploid embryo rate was 13.04%, the abnormal embryo rate was 86.96% in group C. There were no significant differences among the three groups (P = 0.55).
The lowest rate of high quality blastocysts has been for three-way rearrangements and the lowest rate of euploidy has been for double two-way translocations, although no significant difference. Different types of BCCR maybe have little effect on the embryonic molecular karyotype. The difference of influence of BCCR on early embryonic developmentandmolecular karyotypeshould be further studied.
平衡复杂染色体重排（BCCR）是涉及两个或多个染色体和至少三个断裂点的平衡染色体结构异常。它在人群中非常罕见。目的是探讨三种类型的 BCCR 对早期胚胎发育和分子核型的影响差异。
招募了 12 对夫妇，包括 4 对三向重排携带者夫妇（A 组）、3 对双双向易位携带者夫妇（B 组）和 5 对异常 CCR 携带者夫妇（C 组）。在 17 个植入前遗传学检测（PGT）周期中共取回 243 个卵母细胞，其中 207 个可用于受精。胞浆内单精子注射后，181 个卵母细胞正常受精。三组胚胎在第 3 天形成的比例分别为 87.88%、97.78%和 77.14%，差异有统计学意义（P=0.01）。与 B 组相比，C 组胚胎形成率明显较低（P=0.01）。此外，三组高评分囊胚的比例分别为 14.71%、48.15%和 62.96%，差异有统计学意义（P=0.00）。与 B 组和 C 组相比，A 组高评分囊胚的比例明显较低（P=0.00；P=0.00）。对 83 个胚胎的 75 个滋养外胚层细胞和 8 个卵裂球进行了综合染色体分析。除 7 个胚胎未能扩增外，9.01%的胚胎被诊断为整倍体，90.91%的胚胎被诊断为异常。对于 A 组，整倍体胚胎的比例为 10.71%，异常胚胎的比例为 89.29%。B 组整倍体胚胎比例为 3.85%，异常胚胎比例为 96.15%。C 组整倍体胚胎比例为 13.04%，异常胚胎比例为 86.96%。三组间差异无统计学意义（P=0.55）。
三向重排的高评分囊胚率最低，双双向易位的整倍体率最低，但差异无统计学意义。不同类型的 BCCR 可能对胚胎分子核型影响较小。BCCR 对早期胚胎发育和分子核型的影响差异有待进一步研究。
