Premature menopause - Meeting the needs

The relationship between primary ovarian insufficiency and gene variations: a prospective case-control study

Around 70 percent of cases of Primary Ovarian Insufficiency (POI) etiology remain unexplained. The aim of our study is to contribute to the etiology and genetic background of POI. A total of 37 POI patients and 30 women in the reproductive period were included in this prospective, case-control study between August 2020 and December 2021. The women were examined for 36 genes with next-generation sequencing (NGS) panel. Gene variations were detected in 59.5 percent of the patients in the case group. FSHR p.S680N (rs6166, c.2039 G>A) and FSHR p.A307T (rs6165, c.919 G>A) gene variants, which are most frequently located in exon 10 of the FSHR gene, were detected in both groups. Although it was not found that these gene variants were significantly different between the groups, it was also found that they were significantly different in POI patients under 30 years of age and in those with a family history of POI. Variations were detected in 12 genes in POI patients. Two gene variants (FGFR1 [c.386A>C, rs765615419] and KISS1 [c.58 G>A, rs12998]) were detected in both groups, and the remaining gene variants were detected only in POI patients. No differences were detected between the groups in terms of gene variations. However, the gene variations detected only in POI patients may play a role in the etiology of POI.

Research progress on the premature ovarian failure caused by cisplatin therapy

Cisplatin is a common anticancer drug able to kill tumor cells, but it causes adverse reactions in the kidney, digestive tract, and other systems. The antitumor effects of cisplatin are mainly due to its ability to bind to the DNA in tumor cells to prevent replication, thereby reducing RNA and protein syntheses, leading to cell damage and death. Cisplatin has a wide range of applications; it can be used to treat cervical, thyroid, ovarian, and other cancers. Cisplatin has a beneficial therapeutic effect, but its therapeutic selectivity is poor. In addition to eliminating diseased target cells, cisplatin can damage normal cells; in women of reproductive age being treated for cancer, cisplatin can lead to ovarian function impairment, premature ovarian failure (POF), and/or infertility. Therefore, reducing the adverse effects of cisplatin on ovarian function is an important topic in clinical research. In this paper, we explore the research progress on the POF caused by cisplatin treatment.

Premature ovarian insufficiency - the need for a genomic map

Premature ovarian insufficiency (POI) is a life-long disorder of heterogeneous etiology, presenting as adolescent primary amenorrhea in its most severe form, with an overall incidence of 1%. Idiopathic POI accounts for up to 70% of women with POI; and genomic, genetic, epidemiological, familial and cohort studies demonstrate a genetic component to this condition. Currently, the only genetic tests routinely performed in non-syndromic POI are FMR1 premutation and cytogenetics, the latter specifically for X-chromosome abnormalities. However, a myriad of genetic aberrations has been identified and implicated, some of which act in a monogenic Mendelian fashion. The presence of multiple genetic aberrations and the complexity of POI genomics are hardly surprising since the embryological formation of the primordial oocyte pool, postnatal oogenesis and folliculogenesis are all highly complex pathways. With this review, the aim is to discuss the current genetic etiologies in the emerging field of POI genomics. Promising candidate genes include STAG3, SYCE1, FIGLA, NOBOX, FSHR, BMP15 and INHA. This area has the potential to progress rapidly in light of advances in genomic technologies. The development of a POI genomic map not only will assist in understanding the underlying molecular mechanisms affecting ovarian function but will also be essential in designing predictive and diagnostic gene panels as well as future novel therapeutic strategies.

Tet1 Deficiency Leads to Premature Ovarian Failure

Tet enzymes participate in DNA demethylation and play critical roles in stem cell pluripotency and differentiation. DNA methylation alters with age. We find that Tet1 deficiency reduces fertility and leads to accelerated reproductive failure with age. Noticeably, Tet1-deficient mice at young age exhibit dramatically reduced follicle reserve and the follicle reserve further decreases with age, phenomenon consistent with premature ovarian failure (POF) syndrome. Consequently, Tet1-deficient mice become infertile by reproductive middle age, while age matched wild-type mice still robustly reproduce. Moreover, by single cell transcriptome analysis of oocytes, Tet1 deficiency elevates organelle fission, associated with defects in ubiquitination and declined autophagy, and also upregulates signaling pathways for Alzheimer's diseases, but down-regulates X-chromosome linked genes, such as Fmr1, which is known to be implicated in POF. Additionally, Line1 is aberrantly upregulated and endogenous retroviruses also are altered in Tet1-deficient oocytes. These molecular changes are consistent with oocyte senescence and follicle atresia and depletion found in premature ovarian failure or insufficiency. Our data suggest that Tet1 enzyme plays roles in maintaining oocyte quality as well as oocyte number and follicle reserve and its deficiency can lead to POF.

A novel heterozygous splice-altering mutation in HFM1 may be a cause of premature ovarian insufficiency

Background

Premature ovarian insufficiency (POI) leads to early loss of ovarian function in women aged < 40 years and is highly heterogeneous in etiology. The genetic etiology of this disorder remains unknown in most women with POI.

Methods

Whole-exome sequencing (WES) was used to analyze genetic factors within a Chinese POI pedigree. Bioinformatic analysis was applied to identify the potential genetic cause, and Sanger sequencing confirmed the existence of a mutation within the pedigree. A minigene assay was performed to validate the effect of the mutation on pre-mRNA splicing.

Results

A novel heterozygous missense mutation in HFM1 (c.3470G > A) associated with POI was identified by whole-exome sequencing. This mutation was heterozygous in the affected family members and was absent in the unaffected family members. In silico analysis predicted that the mutation was potentially pathogenic. Bioinformatic splice prediction tools revealed that the mutation was very likely to have a strong impact on splice site function. Results of the minigene assay revealed that the mutation changed the mRNA splicing repertory.

Conclusions

The missense mutation of the HFM1 gene (c.3470G > A) may be a cause of POI. The mutation altered mRNA splicing in cells. This study can provide geneticists with deeper insight into the pathogenesis of POI and aid clinicians in making early diagnoses in affected women.

New MCM8 mutation associated with premature ovarian insufficiency and chromosomal instability in a highly consanguineous Tunisian family

OBJECTIVE

To identify the gene(s) involved in the etiology of premature ovarian insufficiency in a highly consanguineous Tunisian family.

DESIGN

Genetic analysis of a large consanguineous family with several affected siblings.

SETTING

University hospital-based cytogenetics and molecular genetics laboratories.

PATIENT(S)

A highly consanguineous Tunisian family with several affected siblings born to healthy second-degree cousins.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Targeted exome sequencing was performed by next-generation sequencing for affected family members. Mutations were validated by Sanger sequencing. Functional experiments were performed to explore the deleterious effects of the identified mutation. DNA damage was induced by increasing mitomycin C (MMC) concentrations on cultured peripheral lymphocytes.

RESULT(S)

Analysis of the next-generation sequencing data revealed a new homozygous missense mutation in the minichromosome maintenance 8 gene (MCM8).This homozygous mutation (c. 482A>C; p.His161Pro) was predicted to be deleterious and segregated with the disease in the family. MCM8 participates in homologous recombination during meiosis and DNA double-stranded break repair by dimerizing with MCM9. Mcm8 knock out results in an early block in follicle development and small gonads. Given this, we tested the chromosomal breakage repair capacity of homozygous and heterozygous MCM8 p.His161Pro mutation on cultured peripheral lymphocytes exposed to increasing MMC concentrations. We found that chromosomal breakage after MMC exposure was significantly higher in cells from homozygously affected individuals than in those from a healthy control.

CONCLUSION(S)

Our findings provide additional support to the view that MCM8 mutations are involved in the primary ovarian insufficiency phenotype.

Effects of Estradiol on Histological Parameters and Secretory Ability of Pituitary Mammotrophs in Ovariectomized Female Rats

Objective

Estrogen replacement therapy remains current as a therapeutic approach to treat menopausal symptoms and may significantly affect hormone-producing cells in the female pituitaries. The aim of this study was to examine the histological parameters of pituitary mammotrophs and prolactin secretion after chronic estradiol treatment in ovariectomized adult female rats, reflecting premature menopause.

Materials and Methods

In this experimental study, adult female Wistar rats were divided into non-ovariectomized (C), ovariectomized (OVX) and estradiol-treated ovariectomized (OVX+E) groups. Estradiol dipropionate [0.625 mg/kg body mass per day] was administered for four weeks, while the C and OVX groups received vehicle alone. Mammotrophs were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure, while prolactin concentrations were measured by the non-isotopic two-step assay (Delfia) method. Comparison of the differences between groups was performed using one-way analysis of variance (ANOVA) and Tukay (honest significant difference) HSD test.

Results

Ovariectomy caused significant (P<0.05) decreases in mammotroph optical density (OD), volume density (V_V) and number per mm² by 29, 27 and 34%, respectively, in comparison with the C females. In the OVX+E group, significant (P<0.05) increases in OD, cell volume, V_Vand number of mammotrophs per mm² by 181, 15%, 5.8-fold and 5.2-fold, respectively, were observed when compared to OVX animals. The serum prolactin concentration in OVX females was significantly (P<0.05) decreased by 14% in comparison to the C group, while in OVX+E females, prolactin levels were significantly (P<0.05) increased by 53% compared to the OVX controls.

Conclusion

Estradiol supplementation in ovariectomized females is followed by stimulatory histological and secretory changes of the mammotrophs. These results could serve as indicators of possible prolactinome development upon estradiol application in premature menopausal subjects.

Clinical management of osteoporotic vertebral fracture treated with percutaneous vertebroplasty

Our study demonstrated percutaneous vertebroplasty (PVP) is an effective procedure to rapidly reduce back pain in patients affected by acute osteoporotic vertebral compression fractures (OVCFs) assessed by MRI. We confirmed in our sample, femoral bone density impacts more deeply than vertebral T-score and/or BMD on bone strenght, as it is less affected by any interferences. We interestingly found the presence of previous osteoporotic fragility fractures and chronic glucocorticoids therapy should especially negatively influence bone health of our patients. On the other hand, even if both FRAX scores for major osteoporotic fractures and for femoral fractures seemed to globally define a population at major risk for fragility fractures, our analysis is retrospectively done. We choose and suggest a multidisciplinary medical management of these patients, considering OP is a multifactorial disease and OVCFs usually produce lots of different important consequences on general health.

Copy number variation analysis detects novel candidate genes involved in follicular growth and oocyte maturation in a cohort of premature ovarian failure cases

STUDY QUESTION

Can spontaneous premature ovarian failure (POF) patients derived from population-based biobanks reveal the association between copy number variations (CNVs) and POF?

SUMMARY ANSWER

CNVs can hamper the functional capacity of ovaries by disrupting key genes and pathways essential for proper ovarian function.

WHAT IS KNOWN ALREADY

POF is defined as the cessation of ovarian function before the age of 40 years. POF is a major reason for female infertility, although its cause remains largely unknown.

STUDY DESIGN, SIZE, DURATION

The current retrospective CNV study included 301 spontaneous POF patients and 3188 control individuals registered between 2003 and 2014 at Estonian Genome Center at the University of Tartu (EGCUT) biobank.

PARTICIPANTS/MATERIALS, SETTING, METHODS

DNA samples from 301 spontaneous POF patients were genotyped by Illumina HumanCoreExome (258 samples) and HumanOmniExpress (43 samples) BeadChip arrays. Genotype and phenotype information was drawn from the EGCUT for the 3188 control population samples, previously genotyped with HumanCNV370 and HumanOmniExpress BeadChip arrays. All identified CNVs were subjected to functional enrichment studies for highlighting the POF pathogenesis. Real-time quantitative PCR was used to validate a subset of CNVs. Whole-exome sequencing was performed on six patients carrying hemizygous deletions that encompass genes essential for meiosis or folliculogenesis.

MAIN RESULTS AND THE ROLE OF CHANCE

Eleven novel microdeletions and microduplications that encompass genes relevant to POF were identified. For example, FMN2 (1q43) and SGOL2 (2q33.1) are essential for meiotic progression, while TBP (6q27), SCARB1 (12q24.31), BNC1 (15q25) and ARFGAP3 (22q13.2) are involved in follicular growth and oocyte maturation. The importance of recently discovered hemizygous microdeletions of meiotic genes SYCE1 (10q26.3) and CPEB1 (15q25.2) in POF patients was also corroborated.

LIMITATIONS, REASONS FOR CAUTION

This is a descriptive analysis and no functional studies were performed. Anamnestic data obtained from population-based biobank lacked clinical, biological (hormone levels) or ultrasonographical data, and spontaneous POF was predicted retrospectively by excluding known extraovarian causes for premature menopause.

WIDER IMPLICATIONS OF THE FINDINGS

The present study, with high number of spontaneous POF cases, provides novel data on associations between the genomic aberrations and premature menopause of ovarian cause and demonstrates that population-based biobanks are powerful source of biological samples and clinical data to reveal novel genetic lesions associated with human reproductive health and disease, including POF.

STUDY FUNDING/COMPETING INTEREST

This study was supported by the Estonian Ministry of Education and Research (IUT20-43, IUT20-60, IUT34-16, SF0180027s10 and 9205), Enterprise Estonia (EU30020 and EU48695), Eureka's EUROSTARS programme (NOTED, EU41564), grants from European Union's FP7 Marie Curie Industry-Academia Partnerships and Pathways (IAPP, SARM, |EU324509) and Horizon 2020 innovation programme (WIDENLIFE, 692065), Academy of Finland and the Sigrid Juselius Foundation.

Infertility etiologies are genetically and clinically linked with other diseases in single meta-diseases

The present review aims to ascertain whether different infertility etiologies share particular genes and/or molecular pathways with other pathologies and are associated with distinct and particular risks of later-life morbidity and mortality. In order to reach this aim, we use two different sources of information: (1) a public web server named DiseaseConnect ( http://disease-connect.org ) focused on the analysis of common genes and molecular mechanisms shared by diseases by integrating comprehensive omics and literature data; and (2) a literature search directed to find clinical comorbid relationships of infertility etiologies with only those diseases appearing after infertility is manifested. This literature search is performed because DiseaseConnect web server does not discriminate between pathologies emerging before, concomitantly or after infertility is manifested. Data show that different infertility etiologies not only share particular genes and/or molecular pathways with other pathologies but they have distinct clinical relationships with other diseases appearing after infertility is manifested. In particular, (1) testicular and high-grade prostate cancer in male infertility; (2) non-fatal stroke and endometrial cancer, and likely non-fatal coronary heart disease and ovarian cancer in polycystic ovary syndrome; (3) osteoporosis, psychosexual dysfunction, mood disorders and dementia in premature ovarian failure; (4) breast and ovarian cancer in carriers of BRCA1/2 mutations in diminished ovarian reserve; (5) clear cell and endometrioid histologic subtypes of invasive ovarian cancer, and likely low-grade serous invasive ovarian cancer, melanoma and non-Hodgkin lymphoma in endometriosis; and (6) endometrial and ovarian cancer in idiopathic infertility. The present data endorse the principle that the occurrence of a disease (in our case infertility) is non-random in the population and suggest that different infertility etiologies are genetically and clinically linked with other diseases in single meta-diseases. This finding opens new insights for clinicians and reproductive biologists to treat infertility problems using a phenomic approach instead of considering infertility as an isolated and exclusive disease of the reproductive system/hypothalamic-pituitary-gonadal axis. In agreement with a previous validation analysis of the utility of DiseaseConnect web server, the present study does not show a univocal correspondence between common gene expression and clinical comorbid relationship. Further work is needed to untangle the potential genetic, epigenetic and phenotypic relationships that may be present among different infertility etiologies, morbid conditions and physical/cognitive traits.

New NOBOX mutations identified in a large cohort of women with primary ovarian insufficiency decrease KIT-L expression

CONTEXT

Primary ovarian insufficiency (POI) is a major cause of anovulation and infertility in women. This disease affects 1% of women before 40 years, and several genetic causes have been reported.

OBJECTIVE

The aim of the study was to evaluate the prevalence of NOBOX mutations in a new large cohort of women with POI and to characterize these variants and identify a NOBOX novel target gene.

PATIENTS AND METHODS

A total of 213 unrelated patients with POI were screened for NOBOX mutations, and luciferase reporter assays were performed for the mutations identified.

RESULTS

We reported 3 novel and 2 recurrent heterozygous missense NOBOX rare variants found in 12 patients but not in 724 alleles from ethnic-matched individual women with occurrence of menopause at a normal age. Their functional impact had been tested on the classic growth differentiation factor-9 (GDF9) promoter and on KIT-L, a new NOBOX target gene. The p.Gly91Thr, p.Gly111Arg, p.Arg117Trp, p.Lys371Thr, and p.Pro619Leu mutations were deleterious for protein function.

CONCLUSIONS

In our series, 5.6% of the patients with POI displayed heterozygous NOBOX mutations. We demonstrate that KIT-L could be now a direct NOBOX target. These findings replicate the high prevalence of the association between the NOBOX rare variants and POI.

Identifying a novel role for X-prolyl aminopeptidase (Xpnpep) 2 in CrVI-induced adverse effects on germ cell nest breakdown and follicle development in rats

Environmental exposure to endocrine-disrupting chemicals (EDCs) is one cause of premature ovarian failure (POF). Hexavalent chromium (CrVI) is a heavy metal EDC widely used in more than 50 industries, including chrome plating, welding, wood processing, and tanneries. Recent data from U.S. Environmental Protection Agency indicate increased levels of Cr in drinking water from several American cities, which potentially predispose residents to various health problems. Recently, we demonstrated that gestational exposure to CrVI caused POF in F1 offspring. The current study was performed to identify the molecular mechanism behind CrVI-induced POF. Pregnant rats were treated with 25 ppm of potassium dichromate from Gestational Day (GD) 9.5 to GD 14.5 through drinking water, and the fetuses were exposed to CrVI through transplacental transfer. Ovaries were removed from the fetuses or pups on Embryonic Day (ED) 15.5, ED 17.5, Postnatal Day (PND) 1, PND 4, or PND 25, and various analyses were performed. Results showed that gestational exposure to CrVI: 1) increased germ cell/oocyte apoptosis and advanced germ cell nest (GCN) breakdown; 2) increased X-prolyl aminopeptidase (Xpnpep) 2, a POF marker in humans, during GCN breakdown; 3) decreased Xpnpep2 during postnatal follicle development; and 4) increased colocalization of Xpnpep2 with Col3 and Col4. We also found that Xpnpep2 inversely regulated the expression of Col1, Col3, and Col4 in all the developmental stages studied. Thus, CrVI advanced GCN breakdown and increased follicle atresia in F1 female progeny by targeting Xpnpep2.

Are FSHR polymorphisms risk factors to premature ovarian insufficiency?

Premature ovarian insufficiency (POI) is an ovarian dysfunction characterized by increased FSH levels and amenorrhea before 40 years old. In recent years, the search for genetic causes of POI intensified and studies have been published relating the presence of mutations and polymorphisms in genes associated with development, recruitment and oocyte atresia. The aim of this study was to evaluate the presence of FSHR polymorphisms in our population and contribute with the elucidation of POI etiology. To achieve it, we have studied 100 patients with POI (G1), 60 patients with border line levels of FSH (G2) and 123 controls with regular menopause onset. Cytogenetic analysis of patients' samples and genotyping of Asn680Ser and Ala307Thr polymorphisms were performed in cases and controls. Cytogenetic analysis showed that 92% of G1 patients had normal karyotype, 4% presented polymorphic variants, 3% presented mosaic karyotype involving X chromosome. In G2, 91.6% had normal karyotype results, 3.2% displayed polymorphic variants, and 3.3% presented a mosaic karyotype involving X chromosome. Statistical comparison showed that the polymorphic allele of Ala307Thr polymorphism is more frequent in patients than in controls (G1: p < 0.001 and G2: p = 0.0259). This association has not been previously reported. We concluded that Ala307Thr polymorphism in FSHR can be potentially associated to POI development and can be considered as a screening marker in patients with ovarian failure signals.

Spanish consensus on premature menopause

INTRODUCTION

While we recognise that the term premature menopause is more accepted by most non-specialist health care providers and by the general population, 'primary ovarian insufficiency' (POI) is currently considered the most apposite term to explain the loss of ovarian function, because it better explains the variability of the clinical picture, does not specify definitive failure, and highlights the specific ovarian source. Its pathogenesis involves a congenital reduction in the number of primordial follicles, poor follicle recruitment, or accelerated follicular apoptosis. However, its cause is unknown in most cases.

AIM

This guide analyses the factors associated with the diagnosis and treatment of POI and provides recommendations on the most appropriate diagnostic and therapeutic measures for women under 40 years of age who experience POI.

METHODOLOGY

A panel of experts from various Spanish scientific societies related to POI (Spanish Menopause Society, Spanish Fertility Society, and Spanish Contraception Society) met to reach a consensus on these issues.

RESULTS

Hormonal therapy (HT) is considered the treatment of choice to alleviate the symptoms of hypoestrogenism and to prevent long-term consequences. We suggest that HT should be continued until at least age 51, the average age at natural menopause. The best treatment to achieve pregnancy is oocyte/embryo donation. If a patient is to undergo treatment that will reduce her fertility, she should be informed of this issue and the available techniques to preserve ovarian function, mainly vitrification of oocytes.