Ren Jun, Keqie Yuezhi, Li Yutong, Li Lingping, Luo Min, Gao Meng, Peng Cuiting, Chen Han, Hu Ting, Chen Xinlian, Liu Shanling
Center of Prenatal Diagnosis, Department of Medical Genetics, West China Second University Hospital, Sichuan University, Chengdu, China.
Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China.
Front Genet. 2023 Mar 31;14:1132404. doi: 10.3389/fgene.2023.1132404. eCollection 2023.
Chromosome rearrangement is one of the main causes of abortion. In individuals with double chromosomal rearrangements, the abortion rate and the risk of producing abnormal chromosomal embryos are increased. In our study, preimplantation genetic testing for structural rearrangement (PGT-SR) was performed for a couple because of recurrent abortion and the karyotype of the male was 45, XY der (14; 15)(q10; q10). The PGT-SR result of the embryo in this fertilization (IVF) cycle showed microduplication and microdeletion at the terminals of chromosomes 3 and 11, respectively. Therefore, we speculated whether the couple might have a cryptic reciprocal translocation which was not detected by karyotyping. Then, optical genome mapping (OGM) was performed for this couple, and cryptic balanced chromosomal rearrangements were detected in the male. The OGM data were consistent with our hypothesis according to previous PGT results. Subsequently, this result was verified by fluorescence hybridization (FISH) in metaphase. In conclusion, the male's karyotype was 45, XY, t(3; 11)(q28; p15.4), der(14; 15)(q10; q10). Compared with traditional karyotyping, chromosomal microarray, CNV-seq and FISH, OGM has significant advantages in detecting cryptic and balanced chromosomal rearrangements.
染色体重排是流产的主要原因之一。在患有双重染色体重排的个体中，流产率和产生染色体异常胚胎的风险会增加。在我们的研究中，由于反复流产，对一对夫妇进行了结构重排植入前基因检测（PGT-SR），男方的核型为45, XY der(14; 15)(q10; q10)。该体外受精（IVF）周期中胚胎的PGT-SR结果显示，染色体3和11的末端分别存在微重复和微缺失。因此，我们推测这对夫妇是否可能存在一种核型分析未检测到的隐匿性相互易位。然后，对这对夫妇进行了光学基因组图谱分析（OGM），在男方检测到隐匿性平衡染色体重排。根据之前的PGT结果，OGM数据与我们的假设一致。随后，该结果在中期通过荧光原位杂交（FISH）得到验证。总之，男方的核型为45, XY, t(3; 11)(q28; p15.4), der(14; 15)(q10; q10)。与传统的核型分析、染色体微阵列、CNV-seq和FISH相比，OGM在检测隐匿性和平衡染色体重排方面具有显著优势。
