Hu Xiao, Wang Weili, Cheng Dehua, Gu Yifan, Wan Zhenxing, Dai Jing, Zhang Yi, Luo Keli, Li Wen, Zhang Qianjun, Gong Fei, Lu Guangxiu, Tan Yue-Qiu, Lin Ge, Du Juan
Hunan Guangxiu Hospital Affiliated with Hunan Normal University, Hunan Normal University, Changsha, 410017, China.; Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, 410008, China.; College of Life Science, Hunan Normal University, Changsha, 410081, China.
Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, 410008, China.
Reprod Biomed Online. 2025 Aug;51(2):104879. doi: 10.1016/j.rbmo.2025.104879. Epub 2025 Feb 27.
Preimplantation genetic testing for monogenic diseases (PGT-M) is based on mutation testing combined with linkage analysis; so, how should PGT-M for patients with facioscapulohumeral dystrophy type 1 (FSHD1) be conducted when direct mutation testing is unavailable and specific linked markers are lacking?
Patients with a definite FSHD1 diagnosis who intended to prevent the transmission of the condition to their children were recruited in the Reproductive and Genetic Hospital of CITIC-Xiangya, China between May 2021 and December 2023. Familial genetic risk was evaluated using Bionano, 4q haplotyping and whole-exome sequencing. Linkage markers near the causative 4q35 D4Z4 repeats were identified using targeted sequencing and MicroSeq. Haplotype analysis was conducted to determine affected and unaffected embryos. Embryo diagnosis rate was evaluated. Prenatal diagnosis through amniocentesis was offered at second trimester.
Six patients with FSHD1 were included. During the pre-examination process of PGT-M, a single nucleotide polymorphism 3.5 kb upstream of the affected region using MicroSeq was identified, which could reduce misdiagnosis caused by recombination. A 4q-haplotype fast-determination method was used for determining 4qA and 4qB haplotypes, which could serve as downstream linkage markers. During PGT-M process, 34 blastocysts were evaluated for six families, with a diagnosis rate of 100%. Prenatal diagnosis using Bionano showed a normal 4q35 genotype in four families. Four healthy babies were born after six embryo transfers for five women.
Selecting effective linkage markers for PGT-M in FSHD1-affected regions is challenging. Successful PGT-M for FSHD1 is reported, which is of great clinical significance for genetic counselling and reproductive intervention for this disease.
单基因疾病的植入前基因检测（PGT-M）基于突变检测与连锁分析相结合；那么，当无法进行直接突变检测且缺乏特定连锁标记时，对于1型面肩肱型肌营养不良症（FSHD1）患者应如何进行PGT-M？
2021年5月至2023年12月期间，在中国中信湘雅生殖与遗传医院招募了确诊为FSHD1且打算防止该病遗传给子女的患者。使用Bionano、4q单倍型分析和全外显子测序评估家族遗传风险。使用靶向测序和MicroSeq在致病的4q35 D4Z4重复序列附近鉴定连锁标记。进行单倍型分析以确定受影响和未受影响的胚胎。评估胚胎诊断率。在孕中期通过羊膜穿刺术进行产前诊断。
纳入6例FSHD1患者。在PGT-M的预检过程中，使用MicroSeq在受影响区域上游3.5 kb处鉴定出一个单核苷酸多态性，可减少重组引起的误诊。使用一种4q单倍型快速确定方法来确定4qA和4qB单倍型，其可作为下游连锁标记。在PGT-M过程中，对6个家庭的34个囊胚进行了评估，诊断率为100%。使用Bionano进行的产前诊断显示4个家庭的4q35基因型正常。5名女性进行6次胚胎移植后出生了4名健康婴儿。
为FSHD1受影响区域的PGT-M选择有效的连锁标记具有挑战性。报道了FSHD成功的PGT-M，这对该疾病的遗传咨询和生殖干预具有重要的临床意义。
