Medical Genetics Centre, Northwest Women's and Children's Hospital, Xi'an, China.
Assisted Reproduction Centre, Northwest Women's and Children's Hospital, Xi'an, China.
Syst Biol Reprod Med. 2022 Feb;68(1):80-88. doi: 10.1080/19396368.2021.2005718. Epub 2021 Dec 16.
This study describes a successful case of preimplantation genetic testing for the monogenic disease (PGT-M) of methylmalonic acidemia (MMA). To avoid the transmission of pathogenic mutations and unnecessary pregnancy termination we applied next-generation sequencing (NGS)-based haplotyping on a couple with a previously deceased MMA offspring. After embryo preparation, all samples were amplified successfully by whole genome amplification. We performed preimplantation genetic testing for aneuploidy (PGT-A) to determine the copy number of embryos' chromosomes. PGT-A results showed five blastocysts (2, 11, 14, 15 and 16) with balanced chromosomes (46, XN). Two techniques were used for PGT-M. Sanger sequencing was used to detect the mutations of gene directly, and NGS-based single nucleotide polymorphism (SNP) haplotyping was used to distinguish the chromosomes that carried the mutation. Sanger sequencing and NGS-based SNP haplotyping confirmed that samples 2 and 15 carried c.730insTT, samples 11 and 15 carried c.1105 C > T and samples 14 and 16 did not carry any mutation. Thus, blastocyst 14 was transferred into the mother's uterus. After prenatal diagnosis at 18 weeks of gestation, a healthy infant without mutation was born at full term. This study highlights the efficiency of NGS-based SNP haplotyping for PGT-M of MMA.: MMA: methylmalonic acidemia; MMUT: methylmalonyl-CoA mutase; PGT-M: preimplantation genetic testing for monogenic disease; PGD: preimplantation genetic diagnosis; IVF: in vitro fertilization; ADO: allele dropout; WGA: whole genome amplification; SNP: single nucleotide polymorphism; NGS: next-generation sequencing; PND: prenatal diagnosis; ICSI: intracytoplasmic sperm injection; TE: trophectoderm; DOP-PCR: degenerate oligonucleotide primed polymerase chain reaction; PGT-A: preimplantation genetic testing for aneuploidy; PCR: polymerase chain reaction.
本研究描述了一例甲基丙二酸血症（MMA）单基因疾病（PGT-M）的胚胎植入前遗传学检测成功案例。为避免致病性突变的传递和不必要的妊娠终止，我们对一对先前有 MMA 死产儿的夫妇应用了基于下一代测序（NGS）的单体型分析。胚胎制备后，所有样本均通过全基因组扩增成功扩增。我们进行了胚胎植入前非整倍体检测（PGT-A）以确定胚胎染色体的拷贝数。PGT-A 结果显示有五个囊胚（2、11、14、15 和 16）具有平衡染色体（46，XN）。我们使用了两种技术进行 PGT-M。Sanger 测序直接用于检测基因突变，NGS 单核苷酸多态性（SNP）单体型分析用于区分携带突变的染色体。Sanger 测序和 NGS-SNP 单体型分析证实，样本 2 和 15 携带 c.730insTT，样本 11 和 15 携带 c.1105C>T，样本 14 和 16 未携带任何突变。因此，将囊胚 14 移植到母亲子宫内。在 18 周妊娠时进行产前诊断后，足月分娩出一名无突变的健康婴儿。本研究强调了 NGS-SNP 单体型分析在 MMA 的 PGT-M 中的有效性。MMA：甲基丙二酸血症；MMUT：甲基丙二酰辅酶 A 变位酶；PGT-M：单基因疾病的胚胎植入前遗传学检测；PGD：胚胎植入前遗传学诊断；IVF：体外受精；ADO：等位基因缺失；WGA：全基因组扩增；SNP：单核苷酸多态性；NGS：下一代测序；PND：产前诊断；ICSI：胞质内精子注射；TE：滋养外胚层；DOP-PCR：简并寡核苷酸引物聚合酶链反应；PGT-A：非整倍体的胚胎植入前遗传学检测；PCR：聚合酶链反应。
