Search Results (176)

Background: Preimplantation genetic testing for polygenic diseases (PGT-P) is a reproductive technology that has made it possible to assign risk scores to embryos for various complex polygenic conditions such as diabetes, hypertension, breast cancer, and schizophrenia. Whether there is public interest in utilizing PGT-P and what public opinions are regarding this technology is unknown. Therefore, the objective of our study was to evaluate the opinion of the general United States (US) public regarding PGT-P. Methods: A web-based questionnaire consisting of 25 questions was administered to a nationally representative sample of adult US residents according to age and sex. The survey contained a description of PGT-P, followed by questions with Likert-scale responses ranging from strongly agree to strongly disagree. Results: Of the 715 respondents recruited, 673 (94%) completed the survey. Most respondents agreed that use of PGT-P is ethical (54%), and another 37% were neutral; however, approximately 9% of respondents disagreed and were opposed to the use of PGT-P. Those that opposed PGT-P cited that it was “unethical” (46%) or “not natural” (39%), believed children could be negatively affected (31%), or stated that it went against their religion (15%). The majority of respondents did not know whether PGT-P was safe for embryos (68%) or children (67%) and felt that anyone should be able to utilize it (53%). Conclusions: Participants who were younger, were Atheist, or were Democrats were more likely to agree that “PGT-P is ethical”. This study identified that more than half of respondents supported the use of PGT-P. However, concerns regarding its safety and ethical implications persist. Full article

Background/Objectives: Embryo selection in IVF is traditionally based on morphology, yet many high-quality embryos fail to implant. Preimplantation genetic testing for aneuploidy (PGT-A) using next-generation sequencing (NGS) has been proposed to improve selection by identifying euploid embryos. However, its effectiveness in women of advanced maternal age remains unclear due to limited randomized data. This pilot trial assessed the feasibility of a full-scale RCT comparing PGT-A to morphology-based selection in women aged 35–42. Methods: This single-centre, two-arm parallel RCT (NCT05009745) enrolled women aged 35–42 undergoing IVF/ICSI with ≥3 good-quality day-3 embryos. Participants were randomized (1:1) to either embryo selection by morphology with fresh transfer or PGT-A with frozen transfer of a single euploid embryo. Allocation concealment was achieved via a secure web-based randomization platform; patients and clinicians were unblinded, but the biostatistician remained blinded. The primary outcome was feasibility of recruitment, randomization, and adherence. Results: Between June 2021 and January 2023, 138 women consented (recruitment rate: 55.8%, 95% CI: 49.7–62.0%) and 100 were randomized. Protocol adherence was 94%. Barriers to recruitment included preference for private PGT-A (19%) or fresh transfer (6%). Among biopsied embryos, 51.4% were euploid and 6.6% low-level mosaic. Intention-to-treat analysis showed no significant differences between PGT-A and control groups in clinical pregnancy rate (50% vs. 40%), live birth rate (50% vs. 38%), or miscarriage rate (12% vs. 8%). Cumulative live birth rate after up to three SETs was 72% vs. 52%, respectively (p > 0.05). No multiple pregnancies occurred. Conclusions: RCTs of PGT-A in older women are feasible. A multicentre design with broader inclusion criteria could improve recruitment and allow better assessment of clinical benefit. Full article

Background/Objectives: Karyomapping, a genome-wide SNP analysis, has drastically changed the approach to preimplantation genetic testing for monogenic disorders (PGT-M). However, there are cases in which karyomapping cannot be applied due to an insufficient number of informative SNPs. In this study, we aimed to analyze for the first time whether an insufficient number of informative SNPs is related to the family member used as a reference. Methods: For the karyomapping pre-clinical test, in addition to the couple, one of the DNA samples from an additional family member (children, parent, sibling) is used as a reference for phasing the SNP allele. We analyzed 263 couples who underwent karyomapping for PGT-M at the CHA Fertility Center from May 2020 to December 2022. karyomapping data was scanned on an Illumina NextSeq and analyzed through the BlueFuse Multi software version 4.5. Results: Preclinical karyomapping tests were performed in 263 couples with 58 monogenic diseases. Karyomapping was applicable to PGT-M for 241 (91.6%) couples and not applicable for 22 (8.4%) couples. The percentages of “not applicable” cases according to the reference family member were 1.3% (1/80) in the children group, 5.4% (8/148) in the parent group, and 37.1% (13/35) in the sibling group. Among the genetic diseases studied, couples with neurofibromatosis type 1 (6/27, 22.2%) and Kennedy disease (5/5, 100%) had the highest rate of non-applicable cases. Conclusions: Our results suggest that a child or parent may be better than the sibling for karyomapping in PGT-M. These data provide useful information for selecting a reference among the family members for preclinical karyomapping tests. Full article

Background: Charcot–Marie–Tooth disease (CMT) is a genetically and clinically heterogeneous group of progressive peripheral neuropathies. Preimplantation genetic testing for monogenic disorders (PGT-M), a well-established assisted reproductive technology used to detect specific genetic mutations in embryos before implantation, has been used in common CMT subtypes (e.g., CMT1A); however, data on its application across rarer subtypes and in de novo cases remain limited. In this study, we aimed to evaluate the effectiveness of PGT-M using karyomapping in achieving clinical pregnancies and healthy births in families affected by various CMT types, including the previously unreported subtypes CMT1B and CMT2. Methods: We analyzed 31 PGT-M cycles from 13 families with genetically confirmed CMT, including cases of previously unreported subtypes CMT1B and CMT2. A total of 150 embryos were biopsied. Through 19 embryo transfer cycles, 21 embryos were transferred. In one de novo case, karyomapping was performed using amniotic fluid from an affected fetus as a reference. Results: Of the 19 embryo transfers, 15 resulted in clinical pregnancies. Prenatal diagnosis confirmed that all fetuses were unaffected, and all pregnancies resulted in healthy live births. Successful phasing using amniotic fluid from an affected fetus enabled accurate embryo selection and led to the birth of healthy twins. Conclusions: PGT-M using karyomapping is a rapid and reliable method for achieving successful pregnancies in families affected by diverse CMT subtypes, including de novo cases, and supports broader applicability to other monogenic disorders. Full article

We investigated HIV-1 immune evasion mechanisms in a slow progressor (CBJC515) by constructing pseudoviruses expressing autologous Env proteins. Intriguingly, all pseudoviruses exhibited resistance to the broadly neutralizing antibody (bNAb) PGT135. Using site-directed mutagenesis and chimeric Env construction, we identified distinct escape mechanisms: early 2005 strains lost the N332 glycan site, while 2006/2008 strains retained key epitopes but developed resistance through structural modifications in the V1/V4/C2 regions or acquired novel N-glycosylation sites (N398/N611). These findings provide insights into how HIV-1 can escape from N332-directed bNAb responses without altering the epitope itself. Furthermore, chimeric experiments also elucidated regional co-evolution and functional maintenance: the V1V2 region broadly interfered with envelope protein function, while the V3 region may exhibit compensatory activity, restoring functionality and mitigating deleterious polymorphisms in other regions to keep Env antigenic diversity. These results offer valuable mechanistic clues that may inform the development of next-generation HIV-1 vaccines. Full article

This study compared the DuoStim protocol with two conventional follicular phase stimulations for vitrified oocyte accumulation in poor-prognosis patients undergoing PGT-A. A retrospective analysis of 112 IVF cycles was conducted, with 66 cycles among patients undergoing DuoStim (DS-Group) and 46 among patients undergoing conventional follicular phase stimulations (DF-Group). The primary outcome was the time to live birth, while secondary outcomes included clinical pregnancy rate, miscarriage rate, live birth rate, and cumulative live birth rate. The final analysis included 66 patients in the DS-Group and 40 in the DF-Group, as 6 women (13%) in the DF-Group discontinued treatment after the first stimulation. Oocyte yield was similar between groups (8.4 ± 3.9 in DS-Group vs. 8.2 ± 4.0 in DF-Group, p = 0.80), as was the number of euploid blastocysts (0.9 ± 1.2 vs. 1.1 ± 1.1, p = 0.37). The cumulative live birth rate was 22.7% in the DS-Group and 25% in the DF-Group (multivariate odds ratio adjusted for maternal age and male factor: 1.05, p = 0.93). The time to live birth was significantly shorter in the DS-Group (81.5 ± 15.5 days) compared to the DF-Group (153.7 ± 78.2 days, p < 0.001). DuoStim showed similar efficacy but a shorter time to live birth. Full article

Preimplantation genetic testing (PGT) has been used in various forms over the last two decades. PGT involves testing early embryos following in vitro fertilization and has now become an accepted part of genetic testing. Nowadays, PGT serves as a resource for couples who have a family history of monogenic disorders, wherein the fetus is at high risk of inheriting the condition. PGT is also used to improve pregnancy outcomes in IVF patients in cases of recurrent IVF implantation failure, recurrent miscarriages, as well as male factor. It is also used in screening for sex-linked disorders and sourcing stem cells for therapy. The latest PGT direction is polygenic embryo screening (PES, PGT-P), which allows the identification of embryos that are at elevated risk for significant diseases in adulthood, such as coronary artery disease (CAD), diabetes, hypertension, and breast cancer. As the prevalence and the potential for the use of PES grow, fundamental ethical issues have been underlined, raising concerns about the broader implications of genetic testing. This narrative review summarizes indications, methods, applications, and limitations for PGT, with a particular focus on PES. Full article

Preimplantation genetic testing for aneuploidy (PGT-A) is widely used to select euploid embryos for in vitro fertilization (IVF), but its accuracy in predicting the implantation potential for full segmental aneuploid (Seg-A) embryos remains unclear. In this study, we investigated chromosomal concordance between clinically biopsied trophectoderm (TE) and inner cell mass (ICM) in 175 donated blastocysts, which comprised those clinically diagnosed as euploid (13), Seg-A (36), segmental mosaicism (Seg-M) (60), whole-chromosome aneuploid (Who-A) (52), and whole-chromosome mosaicism (14). Using next-generation sequencing (NGS), we found that TE–ICM concordance rates were higher for euploid (85%) and Who-A (94%) embryos but significantly lower for Seg-A (25%) and Seg-M embryos (33%). For Seg-A, the euploidy rate in the ICM was 19% and the euploidy rate in the ICM was 63% for Seg-M. These low concordance rates may be due to technical and biological artifacts of PGT-A for Seg-A. Despite the significant discordance between TE and ICM, a subset of Seg-A embryos demonstrated euploidy. While clinically diagnosed euploid embryos remain the preferred choice, Seg-A embryos should be considered as having implantation potential. In particular, Seg-A results should be clearly distinguished from Who-A results and not routinely categorically discarded. Further research is required to refine the selection criteria, aided by parental karyotyping or re-biopsy, and to develop more reliable embryo assessment methods to ensure the accurate evaluation of reproductive potential and support shared decision making between doctors and patients. Full article

Background: Given the common occurrence of mosaicism and aneuploidy in IVF embryos, our study aimed to retrospectively identify whether specific chromosomal regions or individual chromosomes are predominantly affected in our clinic. Understanding these patterns can improve embryo selection, reduce miscarriage risks, and enhance genetic counseling. At the same time, due to the limited data on potential comorbidities in affected children, our findings aim to support both clinicians and patients in making informed decisions. Methods: The retrospective clinical study included 461 PGT-A biopsies from our clinic database (September 2023–December 2024) to determine whether specific chromosome regions or individual chromosomes (C) are more likely to be mosaic or aneuploid. Results: Among the 461 embryos analyzed in our clinic, the incidence rate of mosaicism was 16.70% whereas the aneuploidy rate was 32.10%. Our results showed that mosaicism tends to target a specific chromosomal region in embryos, namely the chromosome 1 to 9 region, in particular chromosomes 7, 1, 9. On the other hand, aneuploidy targets the chromosomal region chromosome 16 to 22, particularly chromosomes 16, 19, and 22. Conclusions: Our data suggest that mosaicism and aneuploidy affect the genome in an uneven manner and are often concentrated in specific chromosomal regions, with mosaicism primarily affecting the C1–C9 region and aneuploidy targeting the C16–C22 region. These data highlight the need for further research to understand these patterns and the impact of IVF methods on chromosomal targeting. Comparative studies could also be helpful in genetic counseling by clarifying the implications of the levels of mosaicism in the newborn. Full article

In the current clinical psychiatric practice in most of the world, treatment decisions are based on a person’s capacity to make these decisions. When a person lacks the capacity to understand and appreciate treatment decisions, in many jurisdictions a third-party substitute decision maker (SDM) is appointed on his or her behalf in order to promote safety and optimal clinical outcome. In Ontario, Canada, for example, family members (typically) or public guardians are appointed as SDMs, and they form an integral part of the medical–legal system in psychiatric care. Clinicians working with both patients and their SDMs in these circumstances encounter unique challenges and deliver care in specialized ways, though little research has focused on their experiences and reflections. Based on focus group data, this qualitative study uses a descriptive and interpretative phenomenological approach through thematic analysis to examine these aspects from clinicians working in both inpatient and outpatient settings of an urban teaching hospital’s psychiatric services in Toronto, Canada. Seven key themes emerged: Clinicians (1) appreciate hardships and challenges in lives of SDMs and patients—including the challenging emotions and experiences on both sides, and the risks and relational changes from being an SDM; (2) have an understanding of the patient’s situation and respect for patient autonomy and wishes—they are promoter of autonomy and mindful of patients’ prior wishes amidst patients’ fluctuating capacity, facilitating communication, keeping patients informed and promoting transitioning from SDM to self-determination; (3) have a special working relationship with family SDMs—including supporting SDMs, avoiding harm from delayed or denied treatment, and educating and collaborating with SDMs while maintaining professional boundaries; (4) at times find it difficult working with SDMs—stemming from working with over-involved or uninterested family SDMs, coping with perceived poor SDM decisions, and they sometimes ponder if SDMs are necessary; (5) delineate differences between family and Public Guardian and Trustee (PGT) SDMs—they see PGT as closely aligned with medical decision makers, while family SDMs are more intimately involved and more likely to disagree with a physician’s recommendation; (6) recognize the importance of the SDM role in various contexts—through seeing social values in having SDMs, and acknowledging that having SDMS help them to feel better about their actions as they work to protect the patients; and (7) express ideas on how to improve the current system—at public, societal, and family SDM levels. We conclude that clinicians have unique mediating roles, with privilege and responsibility in understanding the different roles and challenges patients and SDMs face, and have opportunities to improve patient and SDM experiences, clinical outcomes, carry out education, and advocate for ethically just decisions. These clinical roles also come with frustration, discomfort, moral distress and at times vicarious trauma. Clinicians’ unique understanding of this complex and nuanced intersection of patient care provides insight into the core issues of autonomy, duty to care and protect, advocacy, and emotional dynamics involved in this sector as a larger philosophical and social movement to abolish SDMs, as advocated by the Convention on the Rights of Persons with Disability (CRPD), is taking place. We briefly discuss the role of supported decision making as an alternative as. Full article

Background/Objectives: Male infertility is becoming a serious problem affecting about 7% of all men worldwide and is a major or contributory factor in 50% of infertile couples overall. Men with abnormal semen parameters have a significantly increased risk of aneuploidy, presenting a serious concern in programmes of assisted reproductive technologies. Recently, the introduction of preimplantation genetic testing for aneuploidies (PGT-A) has increased the pregnancy rate and live births. We investigated the effect of PGT-A on the success of IVF treatment in couples with the male factor of infertility. Methods: Two experimental groups and one control group were studied: Group A (110 couples)—male partners with abnormal semen parameters, with PGT-A; Group B (110 couples)—male partners with abnormal semen parameters, without PGT-A; and Group C (105 couples)—control, male partners with normal spermograms, with PGT-A. A Day 3 blastomere biopsy was followed by FISH-based PGT-A. A total of 880 embryos from Group A and 890 embryos from Group C was analysed. Results: In patients with abnormal semen parameters, embryonic aneuploidy was twice as common compared to the control (13.6% vs. 5.8%, p < 0.001). Group B had the lowest clinical pregnancy rate (28.2%), with two out of three pregnancies ending in a miscarriage. Only 10% of IVF cycles in this group resulted in live birth compared with 35.5% for Group A and 49.5% for Group C. Conclusions: Our data demonstrate that PGT-A screening as part of IVF treatment drastically increases the clinical pregnancy rate and chances of live birth in couples where male partners have semen abnormality. Full article

Combined preimplantation genetic testing of aneuploidy (PGT-A) and monogenic disease (PGT-M) can be achieved through PCR-based whole genome amplification (WGA) and next-generation sequencing (NGS). However, pathogenic variant detection is usually achieved indirectly through single nucleotide polymorphism haplotyping, as direct detection of pathogenic variants is not always possible. We evaluated whether isothermal WGA was suitable for combined PGT-A and PGT-M that also permitted direct detection of repeat expansions and large deletions, in addition to indirect linkage analysis using microsatellite markers. Five-cell replicates from selected cell lines were subjected to isothermal or PCR-based WGA, followed by NGS-based PGT-A and direct and indirect PGT-M of Huntington’s disease and spinal muscular atrophy. Both WGA methods accurately detected aneuploidy and large (10 Mb) segmental imbalances. However, isothermal WGA produced higher genotyping accuracy compared with PCR-based WGA for all analysed microsatellite markers (93.5% vs. 75.6%), as well as at the HTT CAG repeat locus (100% vs. 7.7%) and the SMN1/2 locus (100% vs. 71.8%). These results demonstrate that isothermal WGA is potentially ideal for combined PGT-A and PGT-M that permits both direct and indirect detection of pathogenic variants including repeat expansions and gene deletions. Full article

To minimise the influence of chromosomal abnormalities during IVF treatment, embryos can be screened before transfer using preimplantation genetic testing. This typically involves an invasive trophectoderm biopsy at the blastocyst stage, where 4–8 cells are collected and analysed. However, emerging evidence indicates that, as embryos develop in vitro in culture media, they release cell-free DNA into the media, providing an alternative source of genetic material that can be accessed non-invasively. Spent blastocyst media samples that contain embryo cell-free DNA demonstrate high informativity rates and ploidy concordance when compared with the corresponding trophectoderm, inner cell mass, or whole blastocyst results. However, optimising this non-invasive approach requires several changes to embryo culture protocols, including additional embryo washes to tackle contamination and extending embryo culture time to maximise the amount of cell-free DNA released into the culture media. In this review, we discuss this novel non-invasive approach for aneuploidy detection and embryo prioritisation, as well as the current data and future prospects for utilising cell-free DNA analysis to identify structural rearrangements and single gene disorders. Full article

Composite grids serve as reinforcement in concrete structures, offering alternatives to conventional steel reinforcement. These grids can be fabricated from various materials, including synthetic polymers, metals, and natural fibers. This study explores the use of composite grids as lateral confinement of self-compacting concrete (SCC) cylinders and examines their impact on the failure mode under axial compression. In the experiment, the types of grids and mesh shapes used were plastic grids of diamond mesh (PGD) and regular mesh (PGT), metallic grids of diamond mesh (MGD) and square mesh (MGS), vegetable grids of Alfa fiber mesh, 10 × 10 mm (VGAF-1) and 20 × 20 mm (VGAF-2), and vegetable grids of date palm fibers (VGDF). The binder of SCC mixtures incorporated 10% marble powder as a partial replacement for ordinary Portland cement (OPC). SCC mixtures were tested in the fresh state by measuring the slump flow diameter, V-funnel flow time, L-box blocking ratio, and segregation index. Cylinders with a diameter of 160 mm and a height of 320 mm were made to assess the mechanical properties of hardened SCC mixtures under axial compression. The results indicate that most of the confined cylinders exhibited an increase in ductility compared to unconfined cylinders. Grid types MGD and PGD provided the best performance, with ductility increases of 100.33% and 96.45%, respectively. VGAF-2 cylinders had greater compressive strength than cylinders with other grid types. The findings revealed that the type and mesh shape of the grids affects the failure mode of confined cylinders, but has minimal influence on their modulus of elasticity. This study highlights the potential of lateral grid confinement as a technique for rehabilitating, strengthening, and reinforcing weaker structural concrete elements, thereby improving their mechanical properties and extending the service life of building structures. Full article

Haemoglobinopathies are among the most prevalent genetic disorders globally. In the context of these conditions, preimplantation genetic testing (PGT) plays a pivotal role in preventing genetic diseases in the offspring of carrier parents, reducing the need for pregnancy termination and enabling the selection of compatible sibling donors for potential stem cell transplantation in cases of thalassemia or sickle cell disease. This review explores the evolving role of PGT as a reproductive option for haemoglobinopathy carriers, tracing the development of PGT protocols from patient-specific to comprehensive testing enabled by advanced technologies like next-generation sequencing (NGS). We discuss key technical, biological, and practical limitations of PGT, as well as the ethical considerations specific to haemoglobinopathies, such as the complexity of interpreting genotypes. Emerging technologies, such as whole-genome sequencing, non-invasive PGT, and gene editing, hold significant promise for expanding applications but also raise new challenges that must be addressed. It will be interesting to explore how advancements in technology, along with the changing management of haemoglobinopathies, will impact reproductive choices. It is anticipated that continued research will improve genetic counseling for PGT for haemoglobinopathies, while a careful evaluation of ethical and societal implications is also required. Responsible and equitable implementation of PGT is essential for ensuring that all families at risk can make informed reproductive choices. Full article