Liao Bao-Qiong, Lai Li-Dan, Liu Ru-Tian, Zhang Qi, Lian Wen-Chang, Xie Wu-Ming
Ganzhou Maternal and Child Health Hospital, Ganzhou, Jiangxi 341000, China.
Yikon Genomics Company, Suzhou, Jiangsu 215021, China.
Zhonghua Nan Ke Xue. 2024 Jun;30(6):499-506.
To investigate the application value of single-sperm sequencing in resolving the carrier status of preimplantation genetic testing (PGT) for chromosomal structural rearrangements in Robertsonian translocations.
Haplotypes were constructed by single-sperm isolation combined with single-sperm sequencing for a patient with 45, XY, der(13; 14)(q10; q10). Twenty single-sperm samples were isolated by mechanical braking and subjected to whole-genome amplification (WGA), and then the Asian Screening Array (ASA) gene chip was used to detect the 183 708 single nucleotide polymorphisms (SNP) of the WGA products. The single sperm associated with the translocation that could be used as haplotype inference was detected by copy number variation (CNV) sequencing, and the chromosomal haplotypes with normal and Robertsonian translocations were inferred. Three biopsy samples of embryonic trophoblast cells were used as the objects. After whole-genome amplification, high-throughput sequencing was employed to determine the status of the translocation chromosome carried by the embryos. The available blastocysts were selected for transfer, and the amniotic fluid samples were taken at 18 weeks of gestation to confirm whether the fetus carried the pathogenic mutation.
A total of 6 037 SNP sites were screened by single-sperm sequencing, and 30 sites selected to distinguish normal and translocation haplotypes. Preimplantation haplotype analysis showed that all the three embryos were euploids without Robertsonian translocation chromosome. Genetic testing of amniotic fluid in the second trimester confirmed that the karyotype of the fetus was 46, XN, carrying no Robertsonian translocation chromosome.
For male carriers of Robertsonian translocation, single sperm sequencing can be used to screen SNP sites to construct haplotypes for distinguishing normal and Robertsonian translocation embryos, and to provide a basis for embryo selection by preimplantation chromosomal structural genetic testing.
探讨单精子测序在解析罗伯逊易位染色体结构重排的植入前基因检测（PGT）携带者状态中的应用价值。
对一名45，XY，der(13; 14)(q10; q10)患者，通过单精子分离结合单精子测序构建单倍型。通过机械制动分离20个单精子样本并进行全基因组扩增（WGA），然后使用亚洲筛查芯片（ASA）基因芯片检测WGA产物的183 708个单核苷酸多态性（SNP）。通过拷贝数变异（CNV）测序检测与可用于单倍型推断的易位相关的单精子，并推断正常和罗伯逊易位的染色体单倍型。以3个胚胎滋养层细胞活检样本为研究对象。全基因组扩增后，采用高通量测序确定胚胎携带的易位染色体状态。选择可用的囊胚进行移植，并在妊娠18周时采集羊水样本以确认胎儿是否携带致病突变。
通过单精子测序共筛选出6 037个SNP位点，选择30个位点区分正常和易位单倍型。植入前单倍型分析显示，所有3个胚胎均为整倍体，无罗伯逊易位染色体。孕中期羊水基因检测证实胎儿核型为46，XN，不携带罗伯逊易位染色体。
对于罗伯逊易位男性携带者，单精子测序可用于筛选SNP位点构建单倍型以区分正常和罗伯逊易位胚胎，为植入前染色体结构基因检测选择胚胎提供依据。
