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Human Reproduction Update Aug 2021Miscarriage describes the spontaneous loss of pregnancy before the threshold of viability; the vast majority occur before 12 weeks of gestation. Miscarriage affects...
BACKGROUND
Miscarriage describes the spontaneous loss of pregnancy before the threshold of viability; the vast majority occur before 12 weeks of gestation. Miscarriage affects one in four couples and is the most common complication of pregnancy. Chromosomal abnormalities of the embryo are identified in ∼50% of first trimester miscarriages; aneuploidy accounts for 86% of these cases. The majority of trisomic miscarriages are of maternal origin with errors occurring during meiotic division of the oocytes. Chromosome segregation errors in oocytes may be sporadic events secondary to advancing maternal age; however, there is increasing evidence to suggest possible maternal germline contributions to this.
OBJECTIVE AND RATIONALE
The objective of this review was to appraise critically the existing evidence relating to maternal germline factors associated with pregnancy loss secondary to embryo aneuploidy, identify limitations in the current evidence base and establish areas requiring further research.
SEARCH METHODS
The initial literature search was performed in September 2019 and updated in January 2021 using the electronic databases OVID MEDLINE, EMBASE and the Cochrane Library. No time or language restrictions were applied to the searches and only primary research was included. Participants were women who had suffered pregnancy loss secondary to numerical chromosomal abnormalities of the embryo. Study identification and subsequent data extraction were performed by two authors independently. The Newcastle-Ottawa Scale was used to judge the quality of the included studies. The results were synthesized narratively.
OUTCOMES
The literature search identified 2198 titles once duplicates were removed, of which 21 were eligible for inclusion in this systematic review. They reported on maternal germline factors having variable degrees of association with pregnancy loss of aneuploid origin. The Online Mendelian Inheritance in Man (OMIM) gene ontology database was used as a reference to establish the functional role currently attributed to the genes reported. The majority of the cases reported and included were secondary to the inheritance of maternal structural factors such as Robertsonian translocations, deletions and insertions. Germline factors with a plausible role in aneuploid pregnancy loss of maternal origin included skewed X-inactivation and CGG repeats in the fragile X mental retardation (FMR1) gene. Studies that reported the association of single gene mutations with aneuploid pregnancy loss were conflicting. Single gene mutations with an uncertain or no role in aneuploid pregnancy loss included mutations in synaptonemal complex protein 3 (SYCP3), mitotic polo-like kinase 4 (PLK4) and meiotic stromal antigen 3 (STAG3) spindle integrity variants and 5,10-methylenetetrahydrofolate reductase (MTHFR).
WIDER IMPLICATIONS
Identifying maternal genetic factors associated with an increased risk of aneuploidy will expand our understanding of cell division, non-disjunction and miscarriage secondary to embryo aneuploidy. The candidate germline factors identified may be incorporated in a screening panel for women suffering miscarriage of aneuploidy aetiology to facilitate counselling for subsequent pregnancies.
Topics: Abortion, Spontaneous; Aneuploidy; Cell Cycle Proteins; Chromosome Segregation; Female; Fragile X Mental Retardation Protein; Humans; Maternal Age; Oocytes; Pregnancy; Protein Serine-Threonine Kinases
PubMed: 33969392
DOI: 10.1093/humupd/dmab010 -
Asian Pacific Journal of Cancer... Oct 2017Background: Numerous similarities have been noted between gametogenic and tumorigenic programs in features such as global hypomethylation, immune evasion,...
Background: Numerous similarities have been noted between gametogenic and tumorigenic programs in features such as global hypomethylation, immune evasion, immortalization, meiosis induction, and migration. In addition, aberrant expression of testis specific genes has been detected in various cancers which has led to categorization of these genes as “cancer-testis genes”. Most of the examples identified in this category are protein encoding. However, recent studies have revealed that non-coding RNAs, including long non coding RNAs (lncRNAs), may have essential regulatory roles in telomere biology, chromatin dynamics, modulation of gene expression and genome structural organization. All of these functions are implicated in both gametogenic and tumorigenic programs. Methods: In the present study, we conducted a computerized search of the MEDLINE/PUBMED and Embase databases with the key words lncRNA, gametogenesis, testis and cancer. Results: We found a number of lncRNAs with essential roles and notable expression in both gametogenic and cancer tissues. Conclusions: Comparison between cancer tissues and gametogenic tissues has shown that numerous lncRNAs are expressed in both, playing similar roles in processes modulated by signaling pathways such as Wnt/β-catenin and PI3K/AKT/mTOR. Evaluation of expression patterns and functions of these genes should pave the way to discovery of biomarkers for early detection, prognostic assessment and evaluation of therapeutic responses in cancers.
PubMed: 29072050
DOI: 10.22034/APJCP.2017.18.10.2601 -
Journal of Ovarian Research Mar 2017Mature cystic teratomas are usually found in the ovaries. They are bilateral in 10 to 15% of cases and multiple cystic teratomas may be present in one ovary. The aim of... (Review)
Review
BACKGROUND
Mature cystic teratomas are usually found in the ovaries. They are bilateral in 10 to 15% of cases and multiple cystic teratomas may be present in one ovary. The aim of this study is to clarify if development of mature cystic teratomas of the ovaries in a single host is metachronous or due to autoimplant or recurrence.
CASE PRESENTATION
We report a woman with bilateral mature cystic teratomas of the ovaries. DNA profiles of these teratomas were investigated via short tandem repeat (STR) analysis and methylation statuses were determined via methylation sensitive multiplex ligation-dependent probe amplification methods. The results showed that the cystic teratomas originated from different stages of oogonia or primary oocyte before germinal vesicle stage failure of meiosis I in female gametogenesis. Potentially relevant literature was searched in PubMed database. Cases of bilateral or multiple mature cystic teratomas of the ovaries were analyzed. To date, there has been no reported case of multiple mature cystic teratomas in which clarification of the origin was achieved using molecular genetic methods.
CONCLUSIONS
The results of this case study provide evidence of metachronous development of mature cystic teratomas of the ovaries and may serve as a reference in the management of patients following laparoscopic cystectomy.
Topics: Adult; DNA Copy Number Variations; DNA Methylation; Female; Genetic Loci; Humans; Loss of Heterozygosity; Microsatellite Repeats; Neoplasm Grading; Neoplasms, Second Primary; Ovarian Neoplasms; Sequence Analysis, DNA; Teratoma
PubMed: 28288660
DOI: 10.1186/s13048-017-0313-8 -
Women's Health (London, England) 2022Our review aimed to consolidate the latest update on the application of in vitro maturation among immature oocyte harvest in combination with ovarian tissue...
OBJECTIVES
Our review aimed to consolidate the latest update on the application of in vitro maturation among immature oocyte harvest in combination with ovarian tissue cryopreservation known as ovarian tissue oocyte-in vitro maturation.
METHODS
A thorough search for relevant studies was conducted via PubMed, Google Scholar, EMBASE, and clinical.gov databases up to December 2020. The primary outcome was the oocyte maturation rate, which measured the number of immature oocytes (geminal vesicle stage) that progressed to mature oocytes (meiosis II stage) following in vitro maturation. The secondary outcomes were the fertilization rate following intracytoplasmic sperm injection/in vitro fertilization of these oocytes for the embryo cryopreservation cohort. Our review included pre-pubertal girls and women with cancer who underwent ovarian tissue oocyte-in vitro maturation as fertility preservation.
RESULTS
The primary search identified 207 studies. Twelve manuscripts were selected for inclusion in our review following duplication assessment, title and abstract screening, and full-text evaluation tailored to our inclusion criteria. All the population belonged to a cancer group and underwent concurrent ovarian tissue oocyte-in vitro maturation. A total of 5724 immature oocytes were obtained following ovarian tissue cryopreservation. Approximately 33.84% of the immature oocytes successfully matured via in vitro maturation, which were cryopreserved as oocytes or fertilized as embryos and subsequently stored for future use.
CONCLUSION
Our review proposed the potential application of ovarian tissue oocyte-in vitro maturation in increasing the number of mature oocytes. The acceptable improvement in oocyte maturation rate following in vitro maturation indicates that improving oocyte outcomes is an excellent cost-effective strategy for fertility preservation among women with cancer.
Topics: Cryopreservation; Female; Fertility Preservation; Humans; In Vitro Oocyte Maturation Techniques; Male; Neoplasms; Oocytes; Semen
PubMed: 35983837
DOI: 10.1177/17455057221114269