Preimplantation genetic testing for aneuploidy helps to achieve a live birth with fewer transfer cycles for the blastocyst FET patients with unexplained recurrent implantation failure.

PURPOSE: This retrospective cohort study aimed to investigate the value of preimplantation genetic testing for aneuploidy (PGT-A) as a screening test for patients suffering from unexplained recurrent implantation failure (RIF). METHODS: After screening patients in one reproductive medicine center, twenty-nine, forty-nine and thirty-eight women (< 40 years old) who had suffered unexplained RIF with PGT-A, or RIF without PGT-A, or no RIF with PGT-A were included. The clinical pregnancy rate and live birth rate per transfer, the conservative and optimal cumulative clinical pregnancy rates (CCPR) and live birth rates (CLBR) after three blastocyst FETs were analyzed. RESULTS: The live birth rate per transfer was significantly higher in the RIF + PGT-A group than that in the RIF + NO PGT-A group (47.6% vs. 24.6%, p = 0.014). After 3 cycles of FET, RIF + PGT-A group had significantly higher conservative CLBR and optimal CLBR compared to the RIF + NO PGT-A group (69.0% vs. 32.7%, p = 0.002 and 73.7% vs. 57.5%, p = 0.016), but had similar conservative and optimal CLBRs compared to the NO RIF + PGT-A group. The number of FET cycles required when half women achieved a live birth was 1 in the PGT-A group and 3 in RIF + NO PGT-A group. The miscarriage rates were not different between the RIF + PGT-A and RIF + NO PGT-A, RIF + PGT-A and NO RIF + PGT-A groups. CONCLUSION: PGT-A did be superior in reducing the number of transfer cycles required to achieve a similar live birth rate. Further studies to identify the RIF patients who would benefit most from PGT-A are necessary.

Preimplantation genetic testing for hereditary hearing loss in Chinese population.

PURPOSE: To evaluate the clinical validity of preimplantation genetic testing (PGT) to prevent hereditary hearing loss (HL) in Chinese population. METHODS: A PGT procedure combining multiple annealing and looping-based amplification cycles (MALBAC) and single-nucleotide polymorphisms (SNPs) linkage analyses with a single low-depth next-generation sequencing run was implemented. Forty-three couples carried pathogenic variants in autosomal recessive non-syndromic HL genes, GJB2 and SLC26A4, and four couples carried pathogenic variants in rare HL genes: KCNQ4, PTPN11, PAX3, and USH2A were enrolled. RESULTS: Fifty-four in vitro fertilization (IVF) cycles were implemented, 340 blastocysts were cultured, and 303 (89.1%) of these received a definite diagnosis of a disease-causing variant testing, linkage analysis and chromosome screening. A clinical pregnancy of 38 implanted was achieved, and 34 babies were born with normal hearing. The live birth rate was 61.1%. CONCLUSIONS AND RELEVANCE: In both the HL population and in hearing individuals at risk of giving birth to offspring with HL in China, there is a practical need for PGT. The whole genome amplification combined with NGS can simplify the PGT process, and the efficiency of PGT process can be improved by establishing a universal SNP bank of common disease-causing gene in particular regions and nationalities. This PGT procedure was demonstrated to be effective and lead to satisfactory clinical outcomes.

Single-cell Sequencing Reveals Clearance of Blastula Chromosomal Mosaicism in In Vitro Fertilization Babies.

Although chromosomal mosaic embryos detected by trophectoderm (TE) biopsy offer healthy embryos available for transfer, high-resolution postnatal karyotyping and chromosome testing of the transferred embryos are insufficient. Here, we applied single-cell multi-omics sequencing for seven infants with blastula chromosomal mosaicism detected by TE biopsy. The chromosome ploidy was examined by single-cell genome analysis, with the cellular identity being identified by single-cell transcriptome analysis. A total of 1616 peripheral leukocytes from seven infants with embryonic chromosomal mosaicism and three control ones with euploid TE biopsy were analyzed. A small number of blood cells showed copy number alterations (CNAs) on seemingly random locations at a frequency of 0%-2.5% per infant. However, none of the cells showed CNAs that were the same as those of the corresponding TE biopsies. The blastula chromosomal mosaicism may be fully self-corrected, probably through the selective loss of the aneuploid cells during development, and the transferred embryos can be born as euploid infants without mosaic CNAs corresponding to the TE biopsies. The results provide a new reference for the evaluations of transferring chromosomal mosaic embryos in certain situations.

Variant haplophasing by long-read sequencing: a new approach to preimplantation genetic testing workups.

OBJECTIVE: To apply long-read, third-generation sequencing as a part of a general workup strategy for performing structural rearrangement (PGT-SR) and monogenic disease (PGT-M) embryo testing. DESIGN: Prospective study. SETTING: In vitro fertilization unit. PATIENT(S): Couples presenting for PGT-SR (n = 15) and PGT-M (n = 2). INTERVENTION(S): Blastocyst biopsy with molecular testing for translocation breakpoints or mutations (targets). MAIN OUTCOME MEASURE(S): Detailed, parental-phased, single-nucleotide polymorphism (SNP) profiles around targets for selection of informative polymorphic markers to simplify and facilitate clinical preimplantation genetic testing (PGT) designs that enable discrimination between carrier and noncarrier embryos. RESULT(S): High definition of chromosome breakpoints together with closely phased polymorphic markers was achieved for all 15 couples presenting for PGT-SR. Similarly, for the two couples presenting for PGT-M, tightly linked informative markers around the mutations were also simply identified. Three couples with translocations t(1;17)(q21;p13), t(3;13)(p25;q21.2), and t(12;13)(q23;q22) proceeded with PGT-SR, requesting preferential identification of noncarrier embryos for transfer. Following selection of a set of informative SNPs linked to breakpoints, we successfully performed PGT-SR tests, resulting in ongoing pregnancies with a noncarrier fetus for all couples. Similarly, with the use of tests based on informative SNPs linked to the parental mutations, one couple proceeded with PGT-M for maple syrup urine disease, resulting in an ongoing pregnancy with a disease-free fetus. CONCLUSION(S): For couples contemplating clinical PGT, variant haplophasing around the target reduces the workup process by enabling rapid selection of closely linked informative markers for patient-specific test design.

Chromosome constitution of equal-sized three-cell embryos using next-generation sequencing technology.

PURPOSE: To study the chromosome constitution of equal-sized three-cell embryo. METHODS: We determined the chromosome constitution of 105 blastomeres from 35 embryos using multiple annealing and looping-based amplification cycles (MALBAC) together with NGS sequencing technology. Chromosomal copy number variation (CNV) analysis was successfully performed in 27 embryos. We also analyzed radius, perimeter, area, and volume of each blastomere to explore the possibility of selecting the normal embryos. RESULTS: Majority of the embryos (77.8%, 21/27) studied were mosaic or aneuploid, and only 22.2% (6/27) had normal chromosome numbers. The aneuploid chromosomes spread across all chromosomes and the most frequent aneuploidies were for chromosomes 1, 16, and 18 followed by 13, 19, and 21. Statistical analyses showed no significant difference between euploid and aneuploid embryos regarding radius, perimeter, area, and volume of their blastomeres. CONCLUSIONS: Our results showed that majority of the equal-sized three-cell embryos were chromosomally abnormal and could not be distinguished by morphology observation, so they should be given lower priority at selection for transfer.

Age-related changes in the mitochondria of human mural granulosa cells.

STUDY QUESTION: What changes in the mitochondria of human mural granulosa cells (mGCs) with maternal aging? SUMMARY ANSWER: The mitochondrial membrane potential (MMP) and the ability of oxidative phosphorylation (OXPHOS) of mGCs declines with reproductive aging, accompanied with more abnormal mitochondria. WHAT IS KNOWN ALREADY: Mitochondria play an important role in the dialogue between the mGCs and oocytes. However, the underlying mechanism of mitochondrial dysfunction in mGCs in aging is still poorly understood. STUDY DESIGN SIZE, DURATION: In total, 149 infertile women underwent IVF in the ART Centre of the Chinese PLA General Hospital, China from September 2016 to May 2017. Two age groups were investigated: the young group (<38 years old) and the old group (≥38 years old). PARTICIPANTS/MATERIALS, SETTING, METHODS: The mitochondrial ultrastructure of mGCs was observed by transmission electron microscopy, and real-time quantitative polymerase chain reaction was applied to quantify the mitochondrial DNA (mtDNA) copy number, 4977-bp deleted DNA and mRNA expression of mitochondrial ATP synthases ATP5A1 and ATP5I. MMP was detected by flow cytometry and fluorescence microscopy, respectively. Reactive oxygen species (ROS) was tested by flow cytometry. A luminometer was used to measure the ATP levels and western blot to analyse the OXPHOS complex. MAIN RESULTS AND THE ROLE OF CHANCE: In the young group, mitochondria were mostly round or oval, with a few intact parallel tubular-vesicular cristae and homogenous matrix density, while elongated mitochondria were mainly observed in the old group, which had numerous cristae and more high-density matrix particles. Abnormal mitochondria were more common in aging women (P = 0.012). mtDNA relative copy number was positively correlated with maternal age (r = 0.294, P = 0.009) and we found no one with 4977-bp deleted mitochondria. JC-1 (dye used as an indicator of MMP) ratio in the old group was significantly lower than the young group (3.01 ± 0.21 vs 3.85 ± 0.27, P = 0.033). Intracellular ROS levels between the groups did not differ significantly (P = 0.191). The intracellular ATP level in the young group was 1.75-fold higher than that of the advanced-age group (7.17 ± 1.16 vs 4.15 ± 0.60, P = 0.025). The protein expression of ATP5A1, as one of five proteins of OXPHOS, decreased with aging (P < 0.001). ATP5A1 mRNA expression was negatively correlated with aging (r = -0.341, P = 0.012). LIMITATIONS REASONS FOR CAUTION: The quantity of mGCs from some individual patient, especially an advanced-age individual, was small, which cannot meet the demands of all the detections. WIDER IMPLICATIONS OF THE FINDINGS: mGCs dysfunction with aging is mainly linked to impaired mitochondrial function, especially OXPHOS function. Improving the OXPHOS ability in mGCs should be the focus in resolving infertility among advanced age women and making mGCs the proper mitochondria donor cells in the autologous mitochondria transplantation to oocytes. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the grants of the National High Technology Research and Development Program of China, 863 Program No. SS2015AA020402, and the Key Projects of Military Medical Research, No. BWS11J058. There were no competing interests.

Preferential selection and transfer of euploid noncarrier embryos in preimplantation genetic diagnosis cycles for reciprocal translocations.

OBJECTIVE: To develop and validate a new strategy to distinguish between balanced/euploid carrier and noncarrier embryos in preimplantation genetic diagnosis (PGD) cycles for reciprocal translocations and to successfully achieve a live birth after selective transfer of a noncarrier embryo. DESIGN: Retrospective and prospective study. SETTING: In vitro fertilization (IVF) units. PATIENT(S): Eleven patients undergoing mate pair sequencing for identification of translocation breakpoints, followed by clinical PGD cycles. INTERVENTION(S): Embryo biopsy with 24-chromosome testing to determine carrier status of balanced/euploid embryos. MAIN OUTCOME MEASURE(S): Definition of translocation breakpoints and polymerase chain reaction (PCR) diagnostic primers, correct diagnosis of euploid embryos for carrier status, and a live birth with a normal karyotype after transfer of a noncarrier embryo. RESULT(S): In 9 of 11 patients (82%), translocation breakpoints were successfully identified. In four patients with a term PGD pregnancy established with a balanced/euploid embryo of unknown carrier status, the correct carrier status was retrospectively determined, matching with the cytogenetic karyotype of the resulting newborns. In a prospective PGD cycle undertaken by a patient with a 46,XY,t(7;14)(q22;q24.3) translocation, the four balanced/euploid embryos identified comprised three carriers and one noncarrier. Transfer of the noncarrier embryo resulted in birth of a healthy girl who was subsequently confirmed with a normal 46,XX karyotype. CONCLUSION(S): The combination of mate pair sequencing and PCR breakpoint analysis of balanced reciprocal translocation derivatives is a novel, reliable, and accurate strategy for distinguishing between carrier and noncarrier balanced/euploid embryos. The method has potential application in clinical PGD cycles for patients with reciprocal translocations or other structural rearrangements.

De Novo Paternal FBN1 Mutation Detected in Embryos Before Implantation.

BACKGROUND Marfan syndrome (MFS) is an autosomal dominant disease caused by mutations in the Fibrillin (FBN)1 gene and characterized by disorders in the cardiovascular, skeletal, and visual systems. The diversity of mutations and phenotypic heterogeneity of MFS make prenatal molecular diagnoses difficult. In this study, we used pre-implantation genetic diagnosis (PGD) to identify the pathogenic mutation in a male patient with MFS and to determine whether his offspring would be free of the disease. MATERIAL AND METHODS The history and pedigree of the proband were analyzed. Mutation analysis was performed on the couple and immediate family members. The couple chose IVF treatment and 4 blastocysts were biopsied. PGD was carried out by targeted high-throughput sequencing of the FBN1 gene in the embryos, along with single-nucleotide polymorphism haplotyping. Sanger sequencing was used to confirm the causative mutation. RESULTS c.2647T>C (p.Trp883Arg) was identified as the de novo likely pathogenic mutation in the proband. Whole-genome amplification and sequencing of the 3 embryos revealed that they did not carry the mutation, and 1 blastocyst was transferred back to the uterus. The amniocentesis test result analyzed by Sanger sequencing confirmed the PGD. A premature but healthy infant free of heart malformations was born. CONCLUSIONS The de novo mutation c.2647T>C (p.Trp883Arg) in FBN1 was identified in a Chinese patient with MFS. Embryos without the mutation were identified by PGD and resulted in a successful pregnancy.

Clinical application of next-generation sequencing in preimplantation genetic diagnosis cycles for Robertsonian and reciprocal translocations.

PURPOSE: The purpose of this study was to apply next-generation sequencing (NGS) technology to identify chromosomally normal embryos for transfer in preimplantation genetic diagnosis (PGD) cycles for translocations. METHODS: A total of 21 translocation couples with a history of infertility and repeated miscarriage presented at our PGD clinic for 24-chromosome embryo testing using copy number variation sequencing (CNV-Seq). RESULTS: Testing of 98 embryo samples identified 68 aneuploid (69.4 %) and 30 (30.6 %) euploid embryos. Among the aneuploid embryos, the most common abnormalities were segmental translocation imbalances, followed by whole autosomal trisomies and monosomies, segmental imbalances of non-translocation chromosomes, and mosaicism. In all unbalanced embryos resulting from reciprocal translocations, CNV-Seq precisely identified both segmental imbalances, extending from the predicted breakpoints to the chromosome termini. From the 21 PGD cycles, eight patients had all abnormal embryos and 13 patients had at least one normal/balanced and euploid embryo available for transfer. In nine intrauterine transfer cycles, seven healthy babies have been born. In four of the seven children tested at 18 weeks gestation, the karyotypes matched with the original PGD results. CONCLUSION: In clinical PGD translocation cycles, CNV-Seq displayed the hallmarks of a comprehensive diagnostic technology for high-resolution 24-chromosome testing of embryos, capable of identifying true euploid embryos for transfer.

Molecular analysis of DNA in blastocoele fluid using next-generation sequencing.

BACKGROUND: Preimplantation genetic testing (PGT) requires an invasive biopsy to obtain embryonic material for genetic analysis. The availability of a less invasive procedure would increase the overall efficacy of PGT. The aim of the study was to explore the potential of blastocoele fluid (BF) as an alternative source of embryonic DNA for PGT. METHODS: Collection of BF was performed by aspiration with a fine needle prior to vitrification. BF DNA was subjected to whole-genome amplification (WGA) and analyzed by high-resolution next-generation sequencing (NGS). RESULTS: A high-quality WGA product was obtained from 8 of 11 (72.7 %) samples. Comparison of matching BF and blastomere samples showed that the genomic representation of sequencing reads was consistently similar with respect to density and regional coverage across the 24 chromosomes. A genome-wide survey of the sample sequencing data also indicated that BF was highly representative of known single gene sequences, and this observation was validated by PCR analyses of ten randomly selected genes, with an overall efficiency of 84 %. CONCLUSION: This study provides further evidence that BF is a promising alternative source of DNA for PGT.

The Performance of Whole Genome Amplification Methods and Next-Generation Sequencing for Pre-Implantation Genetic Diagnosis of Chromosomal Abnormalities.

Reliable and accurate pre-implantation genetic diagnosis (PGD) of patient's embryos by next-generation sequencing (NGS) is dependent on efficient whole genome amplification (WGA) of a representative biopsy sample. However, the performance of the current state of the art WGA methods has not been evaluated for sequencing. Using low template DNA (15 pg) and single cells, we showed that the two PCR-based WGA systems SurePlex and MALBAC are superior to the REPLI-g WGA multiple displacement amplification (MDA) system in terms of consistent and reproducible genome coverage and sequence bias across the 24 chromosomes, allowing better normalization of test to reference sequencing data. When copy number variation sequencing (CNV-Seq) was applied to single cell WGA products derived by either SurePlex or MALBAC amplification, we showed that known disease CNVs in the range of 3-15 Mb could be reliably and accurately detected at the correct genomic positions. These findings indicate that our CNV-Seq pipeline incorporating either SurePlex or MALBAC as the key initial WGA step is a powerful methodology for clinical PGD to identify euploid embryos in a patient's cohort for uterine transplantation.

The clinical utility of next-generation sequencing for identifying chromosome disease syndromes in human embryos.

Next-generation sequencing is emerging as a reliable and accurate technology for pre-implantation genetic diagnosis (PGD) of aneuploidies and translocations. The aim of this study was to extend the clinical utility of copy number variation sequencing (CNV-Seq) to the detection of small pathogenic copy number variations (CNVs) associated with chromosome disease syndromes. In preliminary validation studies, CNV-Seq was highly sensitive and specific for detecting small CNV in whole-genome amplification products from three replicates of one and five cell samples, with a resolution in the order of 1-2 Mb. Importantly, the chromosome positions of all CNV were correctly mapped with copy numbers similar to those measured in matching genomic DNA samples. In seven clinical PGD cycles where results were obtained for 34 of 35 blastocysts, CNV-Seq identified 18 blastocysts with aneuploidies, one with an aneuploidy and a 4.98 Mb 5q35.2-qter deletion associated with Sotos syndrome, one with a 6.66 Mb 7p22.1-pter deletion associated with 7p terminal deletion syndrome and 14 with no detectable abnormalities that were suitable for transfer. On the basis of these findings, CNV-Seq displays the hallmarks of a comprehensive PGD technology for detection of aneuploidies and CNVs that are known to affect the development and health of patient's embryos.

Maternal PCBP1 determines the normal timing of pronucleus formation in mouse eggs.

In mammals, pronucleus formation, a landmark event for egg activation and fertilization, is critical for embryonic development. However, the mechanisms underlying pronucleus formation remain unclear. Increasing evidence has shown that the transition from a mature egg to a developing embryo and the early steps of development are driven by the control of maternal cytoplasmic factors. Herein, a two-dimensional-electrophoresis-based proteomic approach was used in metaphase II and parthenogenetically activated mouse eggs to search for maternal proteins involved in egg activation, one of which was poly(rC)-binding protein 1 (PCBP1). Phosphoprotein staining indicated that PCBP1 displayed dephosphorylation in parthenogenetically activated egg, which possibly boosts its ability to bind to mRNAs. We identified 75 mRNAs expressed in mouse eggs that contained the characteristic PCBP1-binding CU-rich sequence in the 3'-UTR. Among them, we focused on H2a.x mRNA, as it was closely related to pronucleus formation in Xenopus oocytes. Further studies suggested that PCBP1 could bind to H2a.x mRNA and enhance its stability, thus promoting mouse pronucleus formation during parthenogenetic activation of murine eggs, while the inhibition of PCBP1 evidently retarded pronucleus formation. In summary, these data propose that PCBP1 may serve as a novel maternal factor that is required for determining the normal timing of pronucleus formation.

Preimplantation genetic diagnosis for a Chinese family with autosomal recessive Meckel-Gruber syndrome type 3 (MKS3).

Meckel-Gruber syndrome type 3 is an autosomal recessive genetic defect caused by mutations in TMEM67 gene. In our previous study, we have identified a homozygous TMEM67 mutation in a Chinese family exhibiting clinical characteristics of MKS3, which provided a ground for further PGD procedure. Here we report the development and the first clinical application of the PGD for this MKS3 family. Molecular analysis protocol for clinical PGD procedure was established using 50 single cells in pre-clinical set-up. After whole genomic amplification by multiple displacement amplification with the DNA from single cells, three techniques were applied simultaneously to increase the accuracy and reliability of genetic diagnosis in single blastomere, including real-time PCR with Taq Man-MGB probe, haplotype analysis with polymorphic STR markers and Sanger sequencing. In the clinical PGD cycle, nine embryos at cleavage-stage were biopsied and subjected to genetic diagnosis. Two embryos diagnosed as free of TMEM67 mutation were transferred and one achieving normal pregnancy. Non-invasive prenatal assessment of trisomy 13, 18 and 21 by multiplex DNA sequencing at 18 weeks' gestation excluded the aneuploidy of the analyzed chromosomes. A healthy boy was delivered by cesarean section at 39 weeks' gestation. DNA sequencing from his cord blood confirmed the result of genetic analysis in the PGD cycle. The protocol developed in this study was proved to be rapid and safe for the detection of monogenic mutations in clinical PGD cycle.

Decreased cofilin1 expression is important for compaction during early mouse embryo development.

Compaction, occurring at the eight-cell stage of mouse development, is the process of cell flattening and polarization by which cellular asymmetry is first established. During this process many molecules and organelles undergo polarized distribution, but the cytoskeletal basis for these distribution specifications remains to be explored. The present study focused on cofilin1, an actin-binding protein that depolymerizes actin filaments. We showed that cofilin1 expression decreased at the compaction stage, and that down-regulation of cofilin1 expression by siRNA microinjection accelerated compaction. Continuous observation using time-lapse video miscroscopy confirmed these findings. That is, the embryonic cells microinjected with anti-cofilin1 antibody exhibit earlier adherence properties compared to uninjected cells. Pronuclear microinjection of a site-directed mutated cofilin1 plasmid, in which cofilin1 is sustained in its active form produced embryos with blastomeres that did not adhere, suggesting that inactivation of cofilin1 is critical for cell flattening and adherence. Fluorescein-phalloidin staining indicated that decreased cofilin1 expression promoted the formation of the apical pole, which is a marker for polarity. Scanning electron microscopy results demonstrated the appearance of microvilli on the outer face of blastomeres in cofilin1 knockdown embryos. Our results suggest that cofilin1 plays an important role in cortical cytoplasmic organization during embryo compaction.

Protein expression profile of the mouse metaphase-II oocyte.

The mature oocyte contains the full complement of maternal proteins required for fertilization, the transition to zygotic transcription, and the beginning stages of embryogenesis. Many of these proteins have yet to be characterized. In this study, two-dimensional electrophoresis (2-DE) of mouse metaphase-II (MII) oocyte proteins, stained with silver staining or Pro-Q Diamond dye, was performed to describe the proteome and phosphoproteome of the mouse oocyte derived from ICR mice. A total of 869 selected protein spots, corresponding to 380 unique proteins, were identified successfully by mass spectrometry, in which 90 protein spots representing 53 unique proteins have been stained with Pro-Q Diamond, indicating that they are in phosphorylated forms. All identified proteins were bioinformatically annotated in detail and compared with the embryonic stem cell (ESC) proteome. A proteome reference database for the mouse oocyte was established from the protein data generated in this study, which can be accessed over the Internet ( http://reprod.njmu.edu.cn/2d). This database is the most detailed mouse oocyte proteomic database to date. It should be valuable in expanding our knowledge of the regulation of signaling in oogenesis, fertilization, and embryo development, while revealing potential mechanisms for epigenetic reprogramming.