The types and frequencies of X chromosome abnormalities in women with reproductive problems.

X chromosome architecture and integrity are essential for normal ovarian function. Both numerical and structural X chromosome abnormalities play an important role in female infertility. This study aims to determine the types and frequency of X chromosome aberrations detected in women referred for cytogenetic investigation due to reproductive problems. 2936 women (average age: 37.5 years) were enrolled in the present study. Peripheral blood karyotyping was performed by conventional cytogenetic techniques. For each woman, 20 G-banded metaphases were studied and in case of suspected mosaicism, analysis was extended to 100 metaphases. 2588/2936 (88.15%) of women had a normal karyotype (46,XX), while 348/2936 (11.85%) had an abnormal one. Thirty-two women (1.09%) carried autosomal chromosome abnormalities and 316 (10.76%) had X chromosome rearrangements. In 311/2936 women (10.59%) X chromosome numerical aberrations were detected (low-level mosaicism) and in 5/2936 cases (0.17%) X structural abnormalities (two with pericentric inversion, one with Xq deletion and two 45,X mosaics, one with an Xp deletion cell line and the other with isochromosome Xq cell line). Low-level X mosaicism was a common finding in women > 35 years, as compared to younger ones (92.93% vs 7.07%), a finding consistent with loss of chromosome X with ageing. Other X chromosome abnormalities were detected in younger women (32.3 ± 4.13 vs. 41.04 ± 4.5 years). The mean age of women with Turner-like phenotype was 28.75 ± 6.6 years. The study confirms that the incidence of X chromosome abnormalities is increased in women with fertility problems and that karyotype is the gold standard for their identification. Genetic counselling is recommended in these cases to provide information concerning available treatment and fertility options.

The impact of preimplantation genetic testing for aneuploidies (PGT-A) on clinical outcomes in high risk patients.

PURPOSE: To investigate whether preimplantation genetic testing for aneuploidy (PGT-A) improves the clinical outcome in patients with advanced maternal age (AMA), recurrent miscarriages (RM), and recurrent implantation failure (RIF). METHODS: Retrospective cohort study from a single IVF center and a single genetics laboratory. One hundred seventy-six patients undergoing PGT-A were assigned to three groups: an AMA group, an RM group, and a RIF group. Two hundred seventy-nine patients that did not undergo PGT-A were used as controls and subgrouped similarly to the PGT-A cohort. For the PGT-A groups, trophectoderm biopsy was performed and array comparative genomic hybridization was used for PGT-A. Clinical outcomes were compared with the control groups. RESULTS: In the RM group, we observed a significant decrease of early pregnancy loss rates in the PGT-A group (18.1% vs 75%) and a significant increase in live birth rate per transfer (50% vs 12.5%) and live birth rate per patient (36% vs 12.5%). In the RIF group, a statistically significant increase in the implantation rate per transfer (69.5% vs 33.3%) as well as the live birth rate per embryo transfer (47.8% vs 19%) was observed. In the AMA group, a statistically significant reduction in biochemical pregnancy loss was observed (3.7% vs 31.5%); however, live birth rates per embryo transfer and per patient were not significantly higher than the control group. CONCLUSION: Our results agree with recently published studies, which suggest caution in the universal application of PGT-A in women with infertility. Instead, a more personalized approach by choosing the right candidates for PGT-A intervention should be followed.

Female Reproductive Ageing and Chromosomal Abnormalities in a Large Series of Women Undergoing IVF.

Chromosomal abnormalities are often detected in women with reproductive problems. This study aimed to investigate the presence and type of chromosomal aberrations in peripheral blood of women undergoing in vitro fertilization (IVF) and their possible association with advanced maternal age (AMA). A total of 1,837 women undergoing IVF between 2016 and 2019 were enrolled in the study. Women were further divided in AMA (≥35 years) and younger women (<35 years). Chromosomal abnormalities were detected by peripheral blood karyotyping using standard cytogenetic techniques. Chromosomal abnormalities were detected in 13.5% of the enrolled women; 1.1% had autosomal abnormalities including reciprocal translocations, inversions, Robertsonian translocations, and a supernumerary marker chromosome, while 12.4% had X chromosome abnormalities. The frequency of chromosomal abnormalities was significantly higher in AMA women than in younger ones (17.4% vs. 3.9%, p < 0.05). Women of AMA exhibited X chromosome mosaicism with a frequency of 16.1%, and mosaic karyotypes with 2 and 3 aneuploid cell lines were more frequently detected. X chromosome mosaicism is the most common karyotypic aberration in women undergoing IVF and has 6-fold increased incidence in AMA women compared to younger ones. The present study verifies previous observations that low-level peripheral blood X chromosome mosaicism and the number of aneuploid cell lines observed in women of AMA could be an indication of aneuploidy and poor quality of oocytes contributing to infertility.

PGT-A: who and when? Α systematic review and network meta-analysis of RCTs.

PURPOSE: Wide controversy is still ongoing regarding efficiency of preimplantation genetic testing for aneuploidy (PGT-A). This systematic review and meta-analysis, aims to identify the patient age group that benefits from PGT-A and the best day to biopsy. METHODS: A systematic search of the literature was performed on MEDLINE/PubMed, Embase and Cochrane Central Library up to May 2020. Eleven randomized controlled trials employing PGT-A with comprehensive chromosomal screening (CCS) on Day-3 or Day-5 were eligible. RESULTS: PGT-A did not improve live-birth rates (LBR) per patient in the general population (RR:1.11; 95%CI:0.87-1.42; n=1513; I2=75%). However, PGT-A lowered miscarriage rate in the general population (RR:0.45; 95%CI:0.25-0.80; n=912; I2=49%). Interestingly, the cumulative LBR per patient was improved by PGT-A (RR:1.36; 95%CI:1.13-1.64; n=580; I2=12%). When performing an age-subgroup analysis PGT-A improved LBR in women over the age of 35 (RR:1.29; 95%CI:1.05-1.60; n=692; I2=0%), whereas it appeared to be ineffective in younger women (RR:0.92; 95%CI:0.62-1.39; n=666; I2=75%). Regarding optimal timing, only day-5 biopsy practice presented with improved LBR per ET (RR: 1.37; 95% CI: 1.03-1.82; I2=72%). CONCLUSION: PGT-A did not improve clinical outcomes for the general population, however PGT-A improved live-birth rates strictly when performed on blastocyst stage embryos of women over the 35-year-old mark.

Molecular Drivers of Developmental Arrest in the Human Preimplantation Embryo: A Systematic Review and Critical Analysis Leading to Mapping Future Research.

Developmental arrest of the preimplantation embryo is a multifactorial condition, characterized by lack of cellular division for at least 24 hours, hindering the in vitro fertilization cycle outcome. This systematic review aims to present the molecular drivers of developmental arrest, focusing on embryonic and parental factors. A systematic search in PubMed/Medline, Embase and Cochrane-Central-Database was performed in January 2021. A total of 76 studies were included. The identified embryonic factors associated with arrest included gene variations, mitochondrial DNA copy number, methylation patterns, chromosomal abnormalities, metabolic profile and morphological features. Parental factors included, gene variation, protein expression levels and infertility etiology. A valuable conclusion emerging through critical analysis indicated that genetic origins of developmental arrest analyzed from the perspective of parental infertility etiology and the embryo itself, share common ground. This is a unique and long-overdue contribution to literature that for the first time presents an all-inclusive methodological report on the molecular drivers leading to preimplantation embryos' arrested development. The variety and heterogeneity of developmental arrest drivers, along with their inevitable intertwining relationships does not allow for prioritization on the factors playing a more definitive role in arrested development. This systematic review provides the basis for further research in the field.

Cytogenetic findings of ectopic endometriotic tissue in women with endometriosis and review of the literature.

OBJECTIVE: To determine chromosome and gene alterations in ectopic endometrial (EM) tissue which may be implicated in the clinical course or the progression of endometriosis and to review the literature concerning the cytogenetic findings of women with endometriosis. STUDY DESIGN: 15 women who underwent laparoscopic endometriosis surgery at the Athens Genesis Clinic were enrolled in the study. Ectopic endometrial tissue was surgically removed and further analyzed by conventional and molecular cytogenetic techniques. Fluoresent in situ hibridization (FISH) with probes for p53, ATM, MYC, MLL1 and IGH genes, the centromeres of chromosomes 7 and 8 and 7q22/7q31 chromosomal regions was carried out. RESULTS: Karyotypic analysis revealed no clonal chromosomal abnormalities. However, an increased frequency of polyploidy (55.6%) and sporadic chromosomal abnormalities (40.0%) concerning chromosomes 9, 11, 17 and X were noticed involving mainly deletions, trisomies or monosomies. FISH analysis showed IGH gene rearrangements in 54% of the EM cases and MLL gene rearrangements in 73% of the examined samples. Normal hybridization patterns were observed for p53, ATM and MYC. The increased frequency of polyploidy shown by conventional karyotyping was also confirmed by FISH. CONCLUSION: Polyploidy, sporadic chromosomal abnormalities, as well as IGH and MLL gene rearrangements, may provoke genetic instability and play a potential role in the development of endometriosis. IGH and MLL gene rearrangements indicate a genetic relation between endometriosis and carcinogenesis. Confirmation of the above gene rearrangements in a large series of women may allow the determination of their possible involvement in the pathogenesis of this complex disease and their possible contribution in the early identification of women in danger for malignant transformation.

Coffin-Siris Syndrome 4-Related Spectrum in a Young Woman Caused by a Heterozygous SMARCA4 Deletion Detected by High-Resolution aCGH.

Coffin-Siris Syndrome 4 is an autosomal dominant congenital malformation syndrome caused by heterozygous mutations in the SMARCA4 gene with its main features being intellectual disability, developmental delay, behavioral abnormalities, and hypoplastic or absent fifth fingernails and fifth distal phalanges. Here, we report a young woman with developmental delay, moderate intellectual disability, and bilateral sensorineural hearing loss, referred for genetic testing. High-resolution chromosomal microarray analysis identified a 428-kb deletion in chromosome 19 which included the SMARCA4 gene. We conclude that haploinsufficiency of SMARCA4 may be a valid pathophysiological mechanism leading to milder Coffin-Siris syndrome phenotypes.

Low-level X Chromosome Mosaicism: A Common Finding in Women Undergoing IVF.

BACKGROUND/AIM: To determine the incidence of X chromosome mosaicism in women undergoing in vitro fertilization (IVF) treatment and present preimplantation genetic testing for aneuploidy (PGT-A) outcome of this group. PATIENTS AND METHODS: A total of 1,058 women undergoing IVF and 154 women with no fertility problems were enrolled in the study. Karyotyping from peripheral blood lymphocytes was performed by conventional cytogenetics. Twenty-nine women with X mosaicism underwent PGT-A by array-comparative genomic hybridization from embryos at the blastocyst stage. RESULTS AND CONCLUSION: Out of 1,058 women undergoing IVF, 166 (15.7%) had an abnormal karyotype. The most common finding (14.6%) was X chromosome mosaicism. Its frequency was higher in women >35 years old and reached 46.1% in those >45 years of age. PGT-A results of 130 blastocysts tested showed that 29/117 (24.8%) were euploid; 17/29 (60%) were transferred and 10/17 (70%) were successfully implanted, indicating that PGT-A may be an option for women with low-level X chromosome mosaicism undergoing IVF in order to improve the likelihood of a successful pregnancy outcome.

Reporting on the Role of miRNAs and Affected Pathways on the Molecular Backbone of Ovarian Insufficiency: A Systematic Review and Critical Analysis Mapping of Future Research.

Ovarian insufficiency is identified as a perplexing entity in the long list of pathologies impairing fertility dynamics. The three distinct classifications of ovarian insufficiency are poor ovarian response, premature ovarian insufficiency/failure, and advanced maternal age, sharing the common denominator of deteriorated ovarian reserve. Despite efforts to define clear lines among the three, the vast heterogeneity and overlap of clinical characteristics renders their diagnosis and management challenging. Lack of a consensus has prompted an empirically based management coupled by uncertainty from the clinicians' perspective. Profiling of patients in the era of precision medicine seems to be the way forward, while the necessity for a novel approach is underlined. Implicating miRNAs in the quest for patient profiling is promising in light of their fundamental role in cellular and gene expression regulation. To this end, the current study sets out to explore and compare the three pathophysiologies-from a molecular point of view-in order to enable profiling of patients in the context of in vitro fertilization treatment and enrich the data required to practice individualized medicine. Following a systematic investigation of literature, data referring to miRNAs were collected for each patient category based on five included studies. miRNA-target pairs were retrieved from the DIANA-TarBase repository and microT-CDS. Gene and miRNA annotations were derived from Ensembl and miRbase. A subsequent gene-set enrichment analysis of miRNA targets was performed for each category separately. A literature review on the most crucial of the detected pathways was performed to reveal their relevance to fertility deterioration. Results supported that all three pathophysiologies share a common ground regarding the affected pathways, naturally attributed to the common denominator of ovarian insufficiency. As evidenced, miRNAs could be employed to explore the fine lines and diverse nature of pathophysiology since they constitute invaluable biomarkers. Interestingly, it is the differentiation through miRNAs and not through the molecular affected pathways that corresponds to the three distinctive categories. Alarming discrepancies among publications were revealed, pertaining to employment of empirical and arbitrary criteria in categorizing the patients. Following bioinformatic analysis, the final step of the current study consisted of a critical analysis of the molecular data sourced, providing a clear and unique insight into the physiological mechanisms involved. It is our intention to contribute to mapping future research dedicated to ovarian insufficiency and to help researchers navigate the overwhelming information published in molecular studies.