preimplantation genetic screening

BACKGROUND: Preimplantation genetic testing (PGT), also referred to as preimplantation genetic diagnosis (PGD), is an advanced reproductive technology used during in vitro fertilization (IVF) cycles to identify genetic abnormalities in embryos prior to their implantation. PGT is used to screen embryos for chromosomal abnormalities, monogenic disorders, and structural rearrangements. DEVELOPMENT OF PGT: Over the past few decades, PGT has undergone tremendous development, resulting in three primary forms: PGT-A, PGT-M, and PGT-SR...

Adrenoleukodystrophy, a rare genetic disease associated with the X chromosome (X-ALD - X-linked adrenoleukodystrophy), predominantly affects males and stems from mutations in the ABCD1 gene, responsible for transporting very long chain fatty acids (VLCFA) into peroxisomes. It leads to adrenal insufficiency (AI) and axonal demyelination. In males, the phenotype varies from isolated adrenocortical insufficiency and progressive myelopathy to cerebral adrenoleukodystrophy (CALD). The aim of this case series is to characterize patients with different clinical presentations of X-ALD with follow-up at a tertiary Portuguese hospital...

INTRODUCTION: Does euploidy of trophectoderm (TE) biopsies correlate with conventional blastocyst morphological, maternal age and implantation potential? METHODS: This is a one-centre, retrospective, observational study. RESULTS: Eight hundred and ninety-three blastocysts were biopsied; 57.73% were euploid. The euploidy rate was found to be significantly higher for the embryos with good morphology of inner cell mass (ICM) and TE. Between ICM and TE morphology variables, TE was more predictive of the euploidy rate...

BACKGROUND: Recurrent implantation failure (RIF) represents a vague clinical condition with an unclear diagnostic challenge that lacks solid scientific underpinning. Although euploid embryos have demonstrated consistent implantation capabilities across various age groups, a unanimous agreement regarding the advantages of preimplantation genetic testing for aneuploidy (PGT-A) in managing RIF is absent. The ongoing discussion about whether chromosomal aneuploidy in embryos significantly contributes to recurrent implantation failure remains unsettled...

OBJECTIVE: We evaluate whether next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) improves the cumulative pregnancy outcomes of patients with unexplained recurrent implantation failure (uRIF) as compared to conventional in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI). PATIENTS AND METHODS: This was a retrospective cohort study (2015-2022). A total of 705 couples diagnosed with uRIF were included in the study...

OBJECTIVE: To explore the genetic etiology of two children with Spinal muscular atrophy with respiratory distress type 1 (SMARD1), and prevent the recurrence of birth defects. METHODS: Two unrelated families who had visited the Obstetrics and Gynecology Medical Center of Drum Tower Hospital from August to November 2021 were selected as the study subjects. Copy number of SMN1 gene exon 7 for the probands and their parents was detected by multiple ligation-dependent probe amplification (MLPA)...

Preimplantation genetic testing (PGT) has emerged as a powerful companion to assisted reproduction technologies. The origins and history of PGT are reviewed here, along with descriptions of advances in molecular assays and sampling methods, their capabilities, and their applications in preventing genetic diseases and enhancing pregnancy outcomes. Additionally, the potential for increasing accuracy and genome coverage is considered, as well as some of the emerging ethical and legislative considerations related to the expanding capabilities of PGT...

As nephrology practice is evolving towards precision medicine, and genetic tests are becoming widely available, basic genetic literacy is increasingly required for clinical nephrologists. Yet, decisions based on results of genetic tests are seldom straightforward. We report a 37-year-old woman with autosomal dominant polycystic kidney disease (ADPKD) who was referred for medically assisted reproduction with monogenic preimplantation genetic testing (PGT-M). The PKD1 and PKD2 genes were screened for pathogenic variants...

OBJECTIVE: The purpose of this study was to compare fresh and frozen-thawed euploid blastocyst transfer protocols following preimplantation genetic screening (PGS) in cases of advanced maternal age. METHODS: A total of 330 patients were examined retrospectively. PGS was performed on the embryos of 146 patients for whom fresh transfers were chosen. In contrast, frozen-thawed euploid single embryo transfer (ET) was selected after PGS for 184 patients, and their embryos were vitrified...

The recent introduction of polygenic risk scores within preimplantation genetic testing (PGT-P) has been met with many concerns. To get more insights into the perspectives of relevant stakeholders on the socio-ethical aspects of PGT-P, an interview study with 31 healthcare professionals involved in reproductive medicine and genetics in Europe and North-America was performed. Healthcare professionals in our study were concerned that PGT-P was going too far in terms of selection, with regards to both medical conditions and non-medical traits...

PURPOSE: The trend of delaying childbirth has resulted in a growing number of advanced-aged women who are opting for preimplantation genetic testing (PGT) to screen for monogenic diseases or structural chromosomal rearrangements (PGT-M and PGT-SR). This increase in demand necessitates the development of a clinical predictive model for live birth outcomes in these women. Therefore, the objective of this study is to construct a comprehensive predictive model that assesses the likelihood of achieving a successful live birth in advanced-aged women undergoing PGT-M and PGT-SR treatments...

Introduction: This study aimed to evaluate the feasibility and necessity of using fluorescence Gap-polymerase chain reaction combined with haplotype analysis in preimplantation genetic testing for SEA-type α-thalassemia. Methods: A total of 26 preimplantation genetic testing biopsy cycles were performed in 25 families from June 2021 to February 2022. All couples were carriers of SEA-type α-thalassemia. Fluorescent Gap-polymerase chain reaction was used for detecting fragment deletion. Subsequently, according to the results of polymerase chain reaction, reference embryos were identified to establish haplotype using single nucleotide polymorphism array, and aneuploidy was screened simultaneously...

PURPOSE: Preimplantation genetic testing for monogenic disorders (PGT-M) allows early diagnosis in embryos conceived in vitro. PGT-M helps to prevent known genetic disorders in affected families and ensures that pathogenic variants in the male or female partner are not passed on to offspring. The trend in genetic testing of embryos is to provide a comprehensive platform that enables robust and reliable testing for the causal pathogenic variant(s), as well as chromosomal abnormalities that commonly occur in embryos...

Maintaining genomic stability is crucial for normal development. At earlier stages of preimplantation development, as the embryonic genome activation is not fully completed, the embryos may be more prone to abnormalities. Aneuploidies are one of the most common genetic causes of implantation failure or first-trimester miscarriages. Apoptosis is a crucial mechanism to eliminate damaged or abnormal cells from the organism to enable healthy growth. Therefore, this study aimed to determine the relationship between the expression levels of genes involved in apoptosis in human aneuploid and euploid blastocysts...

Preimplantation genetic testing is an important part in assisted reproductive technology, which can block the intergenerational inheritance of single gene or chromosomal diseases. Preimplantation genetic testing for polygenic disease risk (PGT-P) is the latest development in the field. It is known that polygenic diseases usually have the characteristics of high incidence, late onset, affecting the quality of life and mental health of patients. On the basis of the development of artificial intelligence and genetic detection technology, PGT-P can analyze genetic material, calculate polygenic risk score turning into incidence probability...

BACKGROUND: Population genetic carrier screening (PGCS) for cystic fibrosis (CF) has been offered to couples in Israel since 1999 and was included in a fully subsidized national program in 2008. We evaluated the impact of PGCS on CF incidence, genetic and clinical features. METHODS: This was a retrospective national study. Demographic and clinical characteristics of children with CF born in Israel between 2008 and 2018 were obtained from the national CF registry and from patients' medical records...

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common autosomal dominant genetic diseases. Whole exome sequencing (WES) is a routine tool for diagnostic confirmation of genetic diseases, and it is usually performed to confirm the clinical diagnosis in ADPKD. Reciprocal translocation is the most common chromosomal structural abnormalities and most of its carriers have normal phenotypes until they are encountered infertility problems in adulthood. However, for the polycystic kidney disease caused by abnormal chromosome structure, WES is difficult to achieve the purpose of gene diagnosis...

BACKGROUND: Gonadotrophin-releasing hormone agonist (GnRHa) downregulates gonadotropin secretion in the pituitary gland. It is used both in ovulation induction protocols and in artificial endometrium preparation. Frozen-thawed embryo transfer to artificially prepared endometrium (FET-APE) is a frequent procedure in vitro fertilization (IVF) which requires GnRHa. It can be used either as a daily low-dose injection or as a single depot injection. It is unclear which of these two regimens is superior for artificial endometrium preparation...

The use of expanded carrier screening (ECS) to assess reproductive risk for autosomal recessive (AR) or X-linked recessive (XLR) conditions has been increasingly integrated into obstetrical care. The aim of this study was to determine what proportion of pediatric patients seen by a medical genetics practice could have had their diagnosis predicted if the parent(s) had undergone currently available ECS at the time of data collection in 2021. A retrospective chart review of patients seen for a medical genetic evaluation at a large academic institution was performed from June 1, 2017, through June 1, 2020...

BACKGROUND: Preimplantation genetic testing for aneuploidy (PGT-A) is an emerging technology that aims to identify euploid embryos for transfer, reducing the risk of embryonic chromosomal abnormalities. However, the clinical benefits of PGT-A in recurrent pregnancy failure (RPF) patients, particularly in young RPF patients, remains uncertain. OBJECTIVE AND RATIONALE: This meta-analysis aimed to determine whether RPF patients undergoing PGT-A had better clinical outcomes compared to those not undergoing PGT-A, thus assessing the value of PGT-A in clinical practice...