Zhang Huakun, Zhou Hongbin, Xie Jiansheng, Wu Shuhua, Fan Jing, Chen Wubin, Lian Wenchang, Yao Jilong, Wu Zhengzhong, Li Xuemei
Reproductive Medicine Center, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, Shenzhen 518000 Guangdong, China; Shenzhen Clinical Research Center for Obstetrics & Gynecology and Reproductive System Diseases, Shenzhen 518000 Guangdong, China.
Prenatal Diagnosis Center, the University of Hong Kong - Shenzhen Hospital, Shenzhen 518053 Guangdong, China.
Eur J Obstet Gynecol Reprod Biol. 2025 Aug 28;314:114677. doi: 10.1016/j.ejogrb.2025.114677.
This study investigates the association between alobar holoprosencephaly (HPE) and de novo germline microdeletions in the Xq25 region. To develop a Preimplantation Genetic Testing for Monogenic Disorders (PGT-M) based workflow enabling high-resolution preimplantation detection of sub-Mb microdeletions, overcoming the >1 Mb resolution limit of conventional whole genome amplification(WGA) copy number variation(CNV) sequencing to identify causative Xq25 variants and prevent pathogenic microdeletion transmission.
This study presents a clinical case involving a couple with an adverse obstetric history accompanied by two occurrences of HPE. Genetic analysis and counseling were performed, followed by haplotype analysis and PGT-M as interventions. The Mutated Allele Revealed by Sequencing with Aneuploidy and Linkage Analyses (MARSALA) technique was utilized as a simple, efficient, and reliable approach for PGT-M.
The primary outcomes were the detection of chromosome microdeletions and the successful selection of embryos lacking Xq25 fragment microdeletions. Pregnancy outcomes, embryo development, and genetic counseling results served as secondary outcomes. We analyzed conception products using chromosome microarray analysis and performed single-nucleotide polymorphism haplotype linkage analysis on biopsy tissues amplified by WGA prior to sequencing. Chromosome abnormalities with microdeletions were identified using the PGT-M-based workflow. Embryo euploidy status was assessed using high-depth copy number variation sequencing.
Among five tested blastocysts, three were euploid (two carrying a maternal mutation and one non-mutant.). Following implantation of the mutation-free euploid blastocyst, a successful pregnancy was achieved. Chromosomal karyotype and chromosome microarray analysis (CMA) analysis of mid-pregnancy amniotic fluid showed normal chromosomes and genetic content, leading to the birth of a healthy, full-term infant.
This study underscores the necessity of maintaining detailed obstetric records, providing genetic counseling, and preserving nonviable fetal genetic material. By integrating the MARSALA technique with selected genetic marker-based SNP linkage analysis under the framework of PGT-M, this study established a method enabling single-cell-level preimplantation diagnosis of various chromosomal microabnormalities.
本研究调查无脑叶全前脑畸形（HPE）与Xq25区域新生种系微缺失之间的关联。开发一种基于单基因疾病植入前基因检测（PGT-M）的工作流程，以实现亚兆碱基微缺失的高分辨率植入前检测，克服传统全基因组扩增（WGA）拷贝数变异（CNV）测序大于1兆碱基的分辨率限制，从而识别致病性Xq25变异并防止致病性微缺失的传递。
本研究介绍了一个临床病例，涉及一对有不良产科病史且两次出现HPE的夫妇。进行了遗传分析和咨询，随后进行单倍型分析和PGT-M作为干预措施。采用测序与非整倍体及连锁分析揭示突变等位基因（MARSALA）技术作为PGT-M的一种简单、高效且可靠的方法。
主要结局是检测染色体微缺失以及成功选择缺乏Xq25片段微缺失的胚胎。妊娠结局、胚胎发育和遗传咨询结果作为次要结局。我们使用染色体微阵列分析分析受孕产物，并在测序前对通过WGA扩增的活检组织进行单核苷酸多态性单倍型连锁分析。使用基于PGT-M的工作流程识别有微缺失的染色体异常。使用高深度拷贝数变异测序评估胚胎整倍体状态。
在五个测试的囊胚中，三个是整倍体（两个携带母系突变，一个无突变）。植入无突变的整倍体囊胚后，成功实现妊娠。孕中期羊水的染色体核型和染色体微阵列分析（CMA）显示染色体和遗传内容正常，产下一名健康的足月婴儿。
本研究强调了保持详细产科记录、提供遗传咨询以及保存无法存活胎儿遗传物质的必要性。通过在PGT-M框架下将MARSALA技术与基于选定遗传标记的SNP连锁分析相结合，本研究建立了一种能够在单细胞水平对各种染色体微异常进行植入前诊断的方法。
