A review of pre-implantation genetic testing technologies and applications

Abstract

The first practice of pre-implantation genetic testing (PGT) was reported more than 30 years ago. PGT, originally named pre-implantation genetic screening (PGS) and pre-implantation genetic diagnosis (PGD), is now categorized as PGT for aneuploidies (PGT-A), PGT for monogenic/single-gene defects (PGT-M), and PGT for chromosomal structural rearrangements (PGT-SR). Patients with fertility issues caused by advanced maternal age, carrier status of chromosomal abnormalities, or harboring pathogenic variant(s) are recommended to undergo PGT to increase the possibility of successful live birth and avoid potentially affected newborns. High-throughput techniques, such as DNA microarrays and next-generation sequencing (NGS), have enabled comprehensive screening of all 24 chromosomes, instead of few loci at a time. Furthermore, as a comprehensive PGT, PGT-Plus was enabled by the rapid development of a genome-wide single-cell haplotyping technique to detect embryo aneuploidy, single-gene disorders, and chromosomal aberrations simultaneously using a single universal protocol. In addition, non-invasive approaches enable a more intact embryo during the biopsy procedure, which may avoid potential mosaicism issues at a certain scale by testing spent culture media (SCM). As a novel PGT application, PGT-P detects genome-wide variations in polygenic diseases, which account for a large proportion of premature human deaths and affect a markedly larger population than monogenic diseases, using polygenic risk score calculation to decrease the potential of affecting complex conditions. Owing to the emergence of new technologies recruited to PGTs, more couples with infertility issues have a promising chance of conceiving a healthy baby, ultimately facilitating the human species to live more prosper.

Whether the log-likelihood ratio-based IVF-PGTA assay is a more efficient method？

“…For each sample, more than 80Mb reads, pair-end reading length 100bp was obtained for potential parental contamination analysis which is based on the B allele frequency (BAF) [19,[34][35][36]. Brie y, suppose that maternal genotype is AA and paternal genotype is BB, and embryo genotype is expected to be heterozygous AB.…”

“…Herein, 10M raw sequencing data of each sample was extracted for both chromosomal ploidy and parental contamination testing. CNVs analysis was conducted using a regular PGT-A analysis algorithm (algorithm-PGT-A) [19,37]. Paternal contamination detection was performed with a contamination prediction model, based on leveraging allele frequencies and linkage disequilibrium.…”

“…Although IVF-ET can signi cantly improve the rate of pregnancy, the rate of implantation failure and risk of miscarriage were higher than that with preimplantation genetic testing (PGT) [17][18][19][20]. In clinical practice, some patients with a history of pregnancy loss attempt to obtain a healthy baby using their cryopreservation embryos when they are eligible for PGT.…”

Integrated Evaluation of Clinical Reproductive Potential Post Embryo Transfer Using Raman Metabolic Spectroscopy of Multistage Culture Medium

“…Changing lifestyle habits, environmental pollution, and psychological factors contribute to this growing trend. More and more patients are seeking assistance from reproductive specialists, and Assisted Reproductive Technology (ART) has seen remarkable advancements in recent years, including the use of new technologies to assess the developmental potential of embryos [2]. However, despite these advances, there are still several limitations that need to be addressed.…”

Preimplantation genetic testing as a means of preventing hereditary congenital myasthenic syndrome caused by RAPSN

“…Preimplantation genetic testing for monogenic diseases (PGT‐M) offers a valuable tool for couples carrying pathogenic variants. By selecting euploid embryos without these variants for transfer, PGT‐M prevents the transmission of monogenic diseases and ultimately results in the birth of a healthy child (De Rycke & Berckmoes, 2020 ; Du et al., 2023 ). One significant advantage of PGT‐M is the avoidance of terminating an affected pregnancy, which can lead to complications (Hu et al., 2021 ).…”