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Background: Pre‐implantation genetic testing for monogenic disorders (PGT‐M) is an effective approach to reducing the incidence of birth defects by preventing the transmission of inherited diseases to offspring. However, there are still controversies regarding the detection methods and transplantation of embryos. This paper aims to evaluate the effectiveness of different detection technologies applied to PGT‐M through a retrospective analysis of clinical detection data. Methods: The carrier status of pathogenic mutations and chromosomal copy number variants (CNVs) in 892 embryos was characterized using next‐generation sequencing (NGS), single‐nucleotide polymorphism (SNP) array, and PCR‐based detection technologies. Clinical data from PGT‐M cases were retrospectively analyzed to assess the effectiveness of these detection methods in identifying genetic abnormalities in embryos. Results: A total of 829 embryos were analyzed, with 63 being unsuccessful. Our study revealed that the success rate of detecting deletional mutations using Gap‐PCR 84.9%, which is lower than that of SNP array (98.7%) and NGS (92.5%). However, no significant difference was observed when detecting point mutations using any of the methods. These findings suggest that, when detecting deletional mutations, SNP array and NGS are more suitable choices compared to Gap‐PCR. While SNP array may have a lower resolution and success rate (80.5%) in analyzing CNVs compared to NGS (95.5%), it may still be useful for revealing certain abnormal types. Conclusion: In conclusion, this study found that SNP analysis is advantageous for identifying polygenic and deletional mutations, whereas NGS is more cost‐efficient for detecting common monogenic diseases. Additionally, SNP‐based haplotyping and PCR‐based direct detection of mutations can be used together to enhance the accuracy and success rates of PGT‐M. Our findings offer valuable insights for PGT technicians in choosing suitable detection methods for patients. [ABSTRACT FROM AUTHOR]

The aim of this study was to provide guidance for better management in the selection of blastocyst to warm in frozen-thawed embryo transfer (FET) cycles. A retrospective cohort follow-up study was conducted that included single autologous frozen blastocyst transfer cycles performed in our Reproductive Medicine Unit from January 2009 to December 2016. The live birth rate (LBR), clinical pregnancy rate (cPR) were increased as blastocyst morphology scores increased, but the miscarriage rate decreased in all groups. In the high-score groups, there were no differences in LBR between D5 and D6, while in the low-score groups, LBR was significantly higher in D5 compared to the D6. With respect to neonatal outcome, there were no differences in all the groups. After binary logistic regression analysis, it was seen that patients' age, thawed cycles, pre-frozen morphology score and developmental rate were independently associated with LBR. These results suggest that for high-scoring blastocyst, the pre-frozen morphological score should be given priority while for low-scoring blastocysts, the developmental rate should be given priority when thawing in FET cycles. [ABSTRACT FROM AUTHOR]

Objective: To improve the accuracy of preimplantation genetic testing (PGT) in deletional α-thalassemia patients., Design: Article., Patients: fifty-two deletional α-thalassemia couples., Interventions: Whole genome amplification (WGA), Next-generation sequencing (NGS) and PCR mutation loci detection., Main Outcome Measures: WGA, Single nucleotide polymorphism (SNP) and PCR mutation loci detection results; Analysis of embryo chromosome copy number variation (CNV)., Results: Multiple Displacement Amplification (MDA) and Multiple Annealing and Looping-Based Amplification Cycles (MALBAC) methods for PGT for deletional α-thalassemia. Blastocyst biopsy samples (n = 253) were obtained from 52 deletional α-thalassemia couples. The results of the comparison of experimental data between groups MALBAC and MDA are as follows: (i) The average allele drop-out (ADO) rate, MALBAC vs. MDA = 2.27% ± 3.57% vs. 0.97% ± 1.4%, P =0.451); (ii) WGA success rate, MALBAC vs. MDA = 98.61% vs. 98.89%, P =0.851; (iii) SNP haplotype success rate, MALBAC vs. MDA = 94.44% vs. 96.68%, P =0.409; (iv) The result of SNP haplotype analysis is consistent with that of Gap-PCR/Sanger sequencing results, MALBAC vs. MDA = 36(36/72, 50%) vs. 151(151/181, 83.43%), P =0; (v) Valid SNP loci, MALBAC vs. MDA = 30 ± 9 vs. 34 ± 10, P =0.02; (vi) The mean CV values, MALBAC vs. MDA = 0.12 ± 0.263 vs. 0.09 ± 0.40, P =0.916; (vii) The average number of raw reads, MALBAC vs. MDA =3244259 ± 999124 vs. 3713146 ± 1028721, P =0; (viii) The coverage of genome (%), MALBAC vs. MDA = 5.02 ± 1.09 vs. 5.55 ± 1.49, P =0.008., Conclusions: Our findings indicate that MDA is superior to MALBAC for PGT of deletional α-thalassemia. Furthermore, SNP haplotype analysis combined with PCR loci detection can improve the accuracy and detection rate of deletional α-thalassemia., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lan, Zhou, He, Shu, Liang, Wei, Luo, Wang, Zhao, Qiu and Huang.)

Objective: To carry out preimplantation genetic testing for monogenic/single gene disorders (PGT-M) for a Chinese family affected with Molybdenum co-factor deficiency due to pathogenic variant of MOCS2 gene., Methods: A family with molybdenum co-factor deficiency who attended to the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region in April 2020 was selected as the research subject. Trophoblast cells were biopsied from blastocysts fertilized by intracytoplasmic sperm injection. Embryos carrying the MOCS2 gene variant and chromosome copy number variation (CNV) of more than 4 Mb were detected by single-cell whole genome amplification, high-throughput sequencing and single nucleotide polymorphism typing. Embryos without or carrying the heterozygous variant and without abnormal chromosome CNV were transplanted. During mid-pregnancy, amniotic fluid sample was collected for prenatal diagnosis to verify the results of PGT-M., Results: Eleven oocytes were obtained, among which three blastocysts were formed through culturing. Results of genetic testing suggested that one embryo was heterozygous for the maternally derived MOCS2 gene variant and without chromosomal CNV. Following embryo transfer, intrauterine singleton pregnancy was attained. Prenatal diagnosis by amniocentesis at 18 weeks of gestation revealed that the MOCS2 gene variant and chromosomal analysis results were both consistent with that of PGT-M, and a healthy male infant was born at 37 +5 weeks of gestation., Conclusion: PGT-M has helped the couple carrying the MOCS2 gene variant to have a healthy offspring, and may become an important method for couples carrying other pathogenic genetic variants.