Premature ovarian failure

Maternal exposure to 4-vinylcyclohexene diepoxide during pregnancy leads to disorder of gut microbiota and bile acid metabolism in offspring

Our previous study reveals that maternal exposure to 4-vinylcyclohexene diepoxide (VCD) during pregnancy causes insufficient ovarian follicle reserve and decreased fertility in offspring. The present study aims to further explore the reasons for the significant decline of fecundity in mice caused by VCD, and to clarify the changes of gut microbiota and microbial metabolites in F1 mice. The ovarian metabolomics, gut microbiota and microbial metabolites were analyzed. The results of ovarian metabolomics analysis showed that maternal VCD exposure during pregnancy significantly reduced the concentration of carnitine in the ovaries of F1 mice, while supplementation with carnitine (isovalerylcarnitine and valerylcarnitine) significantly increased the number of ovulation. The results of 16 S rDNA-seq and microbial metabolites analysis showed that maternal VCD exposure during pregnancy caused disordered gut microbiota, increased abundance of Parabacteroides and Flexispira bacteria that are involved in secondary bile acid synthesis. The concentrations of NorDCA, LCA-3S, DCA and other secondary bile acids increased significantly. Our results indicate that maternal exposure to VCD during pregnancy leads to disorder in gut microbiota and bile acid metabolism in F1 mice, accompanying with decreased ovarian function, providing further evidence that maternal exposure to VCD during pregnancy has intergenerational deleterious effects on offspring.

Current understanding of the genomic abnormities in premature ovarian failure: chance for early diagnosis and management

Premature ovarian failure (POF) is an insidious cause of female infertility and a devastating condition for women. POF also has a strong familial and heterogeneous genetic background. Management of POF is complicated by the variable etiology and presentation, which are generally characterized by abnormal hormone levels, gene instability and ovarian dysgenesis. To date, abnormal regulation associated with POF has been found in a small number of genes, including autosomal and sex chromosomal genes in folliculogenesis, granulosa cells, and oocytes. Due to the complex genomic contributions, ascertaining the exact causative mechanisms has been challenging in POF, and many pathogenic genomic characteristics have yet to be elucidated. However, emerging research has provided new insights into genomic variation in POF as well as novel etiological factors, pathogenic mechanisms and therapeutic intervention approaches. Meanwhile, scattered studies of transcriptional regulation revealed that ovarian cell function also depends on specific biomarker gene expression, which can influence protein activities, thus causing POF. In this review, we summarized the latest research and issues related to the genomic basis for POF and focused on insights gained from their biological effects and pathogenic mechanisms in POF. The present integrated studies of genomic variants, gene expression and related protein abnormalities were structured to establish the role of etiological genes associated with POF. In addition, we describe the design of some ongoing clinical trials that may suggest safe, feasible and effective approaches to improve the diagnosis and therapy of POF, such as Filgrastim, goserelin, resveratrol, natural plant antitoxin, Kuntai capsule et al. Understanding the candidate genomic characteristics in POF is beneficial for the early diagnosis of POF and provides appropriate methods for prevention and drug treatment. Additional efforts to clarify the POF genetic background are necessary and are beneficial for researchers and clinicians regarding genetic counseling and clinical practice. Taken together, recent genomic explorations have shown great potential to elucidate POF management in women and are stepping from the bench to the bedside.

Evaluation of safety, feasibility and efficacy of intra-ovarian transplantation of autologous adipose derived mesenchymal stromal cells in idiopathic premature ovarian failure patients: non-randomized clinical trial, phase I, first in human

Background

Premature ovarian failure (POF) is characterized by the loss of ovarian activity before the age of 40 years. Stem cell therapy has the capability to create a regenerative microenvironment and is a proposed treatment for POF-related infertility due to the presence of renewal folliculogenesis and germ cells in the adult ovaries. In this study, we assessed the safety, feasibility, efficacy and dose adjustment of autologous adipose-derived stromal cells (ADSCs) and their ability to improve ovarian function in POF patients.

Methods

This study was a non-randomized clinical trial, phase I. Nine women with a definitive diagnosis of POF were divided into three groups (n = 3 per group) that received either 5 × 10⁶, 10 × 10⁶, or 15 × 10⁶ autologous ADSCs suspension transplanted in the one ovary. Participants were followed-up at 24 h after the transplantation, and at 1 and 2 weeks, and 1, 2, 3, 6, and 12 months after the transplantation. The primary objective was to evaluate the safety of ADSCs transplantation. Secondary objectives included the effects of ADSCs transplantation on the resumption of menstruation, hormones level (Follicle-stimulating hormone (FSH) and anti-Müllerian hormone), ovarian function (Antral follicle count and ovary volume by ultrasonography evaluation) as well as dose escalation.

Results

Participants had not shown any early-onset possible side effects and secondary complications during follow-up. The menstruation resumption was observed in four patients which established for several months. In the 15 × 10⁶ group, two POF patients had a return of menstruation second months after the intervention. Two other POF patients in 5 × 10⁶ and 10 × 10⁶ cell groups reported menstruation resumption at 1 month after the intervention. We observed decreased serum FSH levels of less than 25 IU/l in four patients. In two patients in 5 × 10⁶ and 10 × 10⁶ cell groups, serum FSH showed an inconsistent decline during a 1 year follow up after ADSCs transplantation. The ovarian volume, AMH, and AFC were variable during the follow-up and no significant differences between cell groups (p > 0.05).

Conclusions

We showed the intra-ovarian embedding of ADSCs is safe and feasible and is associated with an inconsistent decline in serum FSH. This should be further investigated with a large RCT.

Trial registration

NCT02603744, Registered 13 November 2015 - Retrospectively registered, http://www.Clinicaltrials.gov

Association of BMP15 and GDF9 variants to premature ovarian insufficiency

PURPOSE

To identify genetic variation associated to premature ovarian insufficiency (POI).

METHODS

A total of 74 women with POI (group POI), 45 women with increased FSH levels (group high FSH), and 88 controls (non-POI) were studied. Genotyping of BMP15:c.-9C>G (rs3810682), BMP15:c.328+905A>G (rs3897937), and BMP15:c.852C>T (rs17003221); and GDF9:c.134-694G>A (rs4705974), GDF9:c.-31-951G>A (rs11748063), GDF9:c.-152G>C (rs30177), and GDF9:g.1073C>T (rs803224) was performed by the TaqMan methodology. Chi-square and Fisher's exact tests were performed to evaluate the distribution of genotypes, alleles, odds ratio, and the Hardy-Weinberg equilibrium of each variation. Haplotype analysis was performed for each gene considering the case and control groups. Bonferroni's correction was applied to chi-square and Fisher's exact test data, and p values < 0.007 for genotypes and alleles and < 0.006 for haplotypes were considered significant.

RESULTS

It was observed a statistically significant difference in genotype distribution of BMP15:c.852C>T between group POI and controls (p < 0.001). TT and TC genotypes were more frequently observed in group POI. Genotype distribution in case group POI, however, was not in the Hardy-Weinberg equilibrium, due to the increased number of heterozygotes in the sample. Concerning GDF9, no association was found among the studied genetic variants and POI or high FSH groups.

CONCLUSION

It is concluded from the present study that the genotypes CT and TT from BMP15:c.852C>T variation may be risk factors for the development of POI.

Identification of microRNAs in granulosa cells from patients with different levels of ovarian reserve function and the potential regulatory function of miR-23a in granulosa cell apoptosis

This study aimed to determine the microRNA (miRNA) profiles in granulosa cells (GCs) from the follicular fluid (FF) of patients with varying levels of ovarian reserve function. We included 45 women undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment. After collecting GCs from each patient, total RNA was extracted from 12 samples. Using Illumina/deep-sequencing technology, we analyzed the small RNAs in each group. Using the R package, we identified the differentially expressed (DE) miRNAs among patients with varying levels of ovarian reserve function. We identified 20 conserved and 3 novel miRNAs that were upregulated in the poor ovarian response (POR) group and 30 conserved miRNAs and 1 novel miRNA that were upregulated in the polycystic ovary syndrome (PCOS) group. Bioinformatics analysis revealed complementary pairing between miR-23a and the 3'-untranslated region (UTR) of the Sirt1 mRNA. miR-23a can regulate SIRT1 protein expression at the posttranscriptional level in GCs. Overexpressing miR-23a can inhibit the expression of SIRT1, decrease the stimulatory effect of SIRT1 on the ERK1/2 pathway, inhibit the expression of p-ERK1/2, and increase apoptosis in GCs. Previous studies confirmed that miR-23a targets SIRT1 and promotes apoptosis in GCs by inhibiting the ERK1/2 signaling pathway. This study provides a novel perspective regarding the role of miRNAs in the regulation of human GC apoptosis in vitro.

Variation analysis of EXO1 gene in Chinese patients with premature ovarian failure

Exonuclease 1 (EXO1) is required for both DNA repair and meiosis. Inactivation of EXO1 gene in mice leads to infertility. This study aimed to investigate whether variants in the EXO1 gene contribute to human premature ovarian failure (POF). The coding region of EXO1 was sequenced in 186 Han Chinese patients with non-syndromic POF. No plausible mutation was detected. The results suggest that mutations in the coding region of EXO1 may not be responsible for POF in Han Chinese women.

Is the resulting phenotype of an embryo with balanced X-autosome translocation, obtained by means of preimplantation genetic diagnosis, linked to the X inactivation pattern?

OBJECTIVE

To examine if a balanced female embryo with X-autosome translocation could, during its subsequent development, express an abnormal phenotype.

DESIGN

Preimplantation genetic diagnosis (PGD) analysis on two female carriers with maternal inherited X-autosome translocations.

SETTING

Infertility center and genetic laboratory in a public hospital.

PATIENT(S)

Two female patients carriers undergoing PGD for a balanced X-autosome translocations: patient 1 with 46,X,t(X;2)(q27;p15) and patient 2 with 46,X,t(X;22)(q28;q12.3).

INTERVENTION(S)

PGD for balanced X-autosome translocations.

MAIN OUTCOME MEASURE(S)

PGD outcomes, fluorescence in situ hybridization in biopsied embryos and meiotic segregation patterns analysis of embryos providing from X-autosome translocation carriers.

RESULT(S)

Controlled ovarian stimulation facilitated retrieval of a correct number of oocytes. One balanced embryo per patient was transferred and one developed, but the patient miscarried after 6 weeks of amenorrhea. In X-autosome translocation carriers, balanced Y-bearing embryos are most often phenotypically normal and viable. An ambiguous phenotype exists in balanced X-bearing embryos owing to the X inactivation mechanism. In 46,XX embryos issued from an alternate segregation, der(X) may be inactivated and partially spread transcriptional silencing into a translocated autosomal segment. Thus, the structural unbalanced genotype could be turned into a viable functional balanced one. It is relevant that a discontinuous silencing is observed with a partial and unpredictable inactivation of autosomal regions. Consequently, the resulting phenotype remains a mystery and is considered to be at risk of being an abnormal phenotype in the field of PGD.

CONCLUSION(S)

It is necessary to be cautious regarding to PGD management for this type of translocation, particularly in transferred female embryos.

Genetic analysis of BMP4 gene in Chinese Han female population with premature ovarian insufficiency

The bone morphogenetic protein 4 (BMP4) gene is related to development of female reproductive organs in animal models. However, to date, there has been no consensus on the relationship between mutations in BMP4 and premature ovarian insufficiency (POI) in human beings. To analyze variations in BMP4 in Chinese women with POI, we sequenced two coding regions of BMP4 in 99 Han Chinese women with POI after DNA extraction and amplification by polymerase chain reaction (PCR). We found no any mutation in the BMP4 coding regions. Only one SNP rs17563 was detected among women with POI. However, the allele frequency of rs17563 presented no significant differences between POI patients and the international HapMap Project data for CHB and CHD. Our findings suggest that the BMP4 gene may not represent a risk factor in the development of POI among Chinese Han women.

NR5A1 (SF-1) gene variants in a group of 26 young women with XX primary ovarian insufficiency

OBJECTIVE

To determine whether NR5A1 (SF-1) variants are a cause of primary ovarian insufficiency (POI) in 26 young women with similar genetic background.

DESIGN

Genetic and functional mutation study.

SETTING

University hospitals.

PATIENT(S)

Genetic analysis of the NR5A1 gene in 26 XX girls with POI.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

NR5A1 molecular and functional analysis.

RESULT(S)

Genetic analysis revealed a new c.763C>T (p.Arg255Cys) mutation and a recurrent c.437G>C (p.Gly146Ala) variant. Functional analysis of the p.Arg255Cys mutant showed a marked decrease in transactivation on the Cyp11a1 and Amh promoters. The p.Gly146Ala variant was identified significantly more often in the patients (46.1%) than in ancestry-matched control subjects (10%).

CONCLUSION(S)

We identified one new NR5A1 mutation in a patient of our POI cohort (prevalence 3.8%). Moreover, although our study is limited in the number of cases, we report the high frequency of the p.Gly146Ala variant in this cohort compared with the ancestry-matched control subjects. This work highlights the important role of SF-1 in ovarian function.

Clinical characteristics and genetic analysis in women with premature ovarian insufficiency

OBJECTIVE

Premature ovarian insufficiency (POI) is defined as a primary ovarian defect characterized by absent menarche (primary amenorrhea) or premature depletion of ovarian follicles before the age of 40 (secondary amenorrhea) with hypergonadotropism and hypoestrogenism.

METHODS

We studied the clinical, biological, and genetic data related to 50 POI patients with a mean age of menopause of 29 years (94% with secondary amenorrhea, 6% with primary amenorrhea and 15% with a family history of POI). Seventeen patients were affected by endocrine autoimmune diseases, antral follicles were observed in 31 patients by ultrasonography.

RESULTS

Karyotype analysis did not show any abnormality of the X chromosome. No mutation in FSH receptor and GDF-9 genes was reported, while in one patient a variant of BMP-15 gene (A180T) was found. Four patients had fragile X mental retardation 1 gene (FMR1) premutation and one an intermediate sized CGG repeats of the same gene. Two patients with FMR1 premutation were sister and developed secondary amenorrhea at the age of 34 and 37 years. The other two patients presented with oligoamenorrhea at the age of 39 and 34 years. The patient harboured the intermediate sized CGG repeats developed secondary amenorrhea at the age of 33 years.

CONCLUSIONS

The genetic analysis performed on a cohort of patients with POI revealed that 8% had FMR1 premutation and only one patient a previously known variant of BMP-15 gene. No alteration of the karyotype and FSH receptor and GDF-9 genes was evidenced.

Blood cell mitochondrial DNA content and premature ovarian aging

Primary ovarian insufficiency (POI) is a critical fertility defect characterized by an anticipated and silent impairment of the follicular reserve, but its pathogenesis is largely unexplained. The frequent maternal inheritance of POI together with a remarkable dependence of ovarian folliculogenesis upon mitochondrial biogenesis and bioenergetics suggested the possible involvement of a generalized mitochondrial defect. Here, we verified the existence of a significant correlation between blood and ovarian mitochondrial DNA (mtDNA) content in a group of women undergoing ovarian hyperstimulation (OH), and then aimed to verify whether mtDNA content was significantly altered in the blood cells of POI women. We recruited 101 women with an impaired ovarian reserve: 59 women with premature ovarian failure (POF) and 42 poor responders (PR) to OH. A Taqman copy number assay revealed a significant mtDNA depletion (P<0.001) in both POF and PR women in comparison with 43 women of similar age and intact ovarian reserve, or 53 very old women with a previous physiological menopause. No pathogenic variations in the mitochondrial DNA polymerase γ (POLG) gene were detected in 57 POF or PR women with low blood mtDNA content. In conclusion, blood cell mtDNA depletion is a frequent finding among women with premature ovarian aging, suggesting that a still undetermined but generalized mitochondrial defect may frequently predispose to POI which could then be considered a form of anticipated aging in which the ovarian defect may represent the first manifestation. The determination of mtDNA content in blood may become an useful tool for the POI risk prediction.

Differentially expressed plasma microRNAs in premature ovarian failure patients and the potential regulatory function of mir-23a in granulosa cell apoptosis

Recent studies implicate the regulatory function of microRNAs (miRNAs) in oocyte maturation and ovarian follicular development. Differentially expressed miRNAs are found in the plasma of premature ovarian failure (POF) patients and normal cycling women. In this study, miRNA-regulated signaling pathways and related genes were described using Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis. The effect of mir-23a on granulosa cell apoptosis was also studied by examining the protein expression of X-linked inhibitor of apoptosis protein (XIAP) and caspase-3, followed by subsequent counting of apoptotic cells after Hoechst 33258 staining. Both GO analysis and pathway analysis suggested that many signaling pathways, including the AKT signaling pathway, steroid hormone receptor signaling pathways, and others, were regulated by this group of differentially expressed miRNAs. A decrease in XIAP expression (mRNA and protein level) and caspase-3 protein levels and an increase in cleaved caspase-3 protein were observed in human ovarian granulosa cells transfected with pre-mir-23a, along with an increased occurrence of apoptosis. In conclusion, differentially expressed miRNAs in the plasma of POF patients may have regulatory effects on proliferation and apoptosis of granulosa cells by affecting different signaling pathways. Mir-23a may play important roles in regulating apoptosis via decreasing XIAP expression in human ovarian granulosa cells.

Genome-wide linkage in a highly consanguineous pedigree reveals two novel loci on chromosome 7 for non-syndromic familial Premature Ovarian Failure

Background

The human condition known as Premature Ovarian Failure (POF) is characterized by loss of ovarian function before the age of 40. A majority of POF cases are sporadic, but 10–15% are familial, suggesting a genetic origin of the disease. Although several causal mutations have been identified, the etiology of POF is still unknown for about 90% of the patients.

Methodology/Principal Findings

We report a genome-wide linkage and homozygosity analysis in one large consanguineous Middle-Eastern POF-affected family presenting an autosomal recessive pattern of inheritance. We identified two regions with a LOD_max of 3.26 on chromosome 7p21.1-15.3 and 7q21.3-22.2, which are supported as candidate regions by homozygosity mapping. Sequencing of the coding exons and known regulatory sequences of three candidate genes (DLX5, DLX6 and DSS1) included within the largest region did not reveal any causal mutations.

Conclusions/Significance

We detect two novel POF-associated loci on human chromosome 7, opening the way to the identification of new genes involved in the control of ovarian development and function.

Genetic and molecular analysis of a new unbalanced X;18 rearrangement: localization of the diminished ovarian reserve disease locus in the distal Xq POF1 region

BACKGROUND

Diminished ovarian reserve (DOR) is a heterogeneous disorder causing infertility, characterized by a decreased number of oocytes, the genetic cause of which is still unknown.

METHODS AND RESULTS

We describe a family with a new unbalanced X;18 translocation der(X) associated with either fully attenuated or DOR phenotype in the same family. Cytogenetics and array comparative genomic hybridization (aCGH) studies have revealed the same partial Xq monosomy and partial 18q trisomy in both the 32-year-old female with DOR and the unaffected mother. The genetic analysis has defined a subtelomeric deletion spanning 13.3 Mb from Xq27.3 to -Xqter, which covers the premature ovarian failure locus 1 (POF1); and a duplication spanning 13.4 Mb, from 18q22.1 to 18qter. From a parental-origin study, we have inferred that the rearranged X chromosome is maternally derived. The Xq27 and 18q22 breakpoint regions fall in a region extremely rich in long interspersed nuclear element, a class of retrotransposons able to trigger mispairing and unusual crossovers. X-inactivation studies reveal a skewing of der(X) both in the mother and the proband. Therefore, the phenotypic expression of der(X) is fully attenuated in the fertile mother and partially attenuated in the DOR daughter.

CONCLUSIONS

We report on an unbalanced maternally derived translocation (X;18)(q27;q22) with different intra-familial reproductive performances, ranging from fertility to DOR. Skewed X-inactivation seems to restore the unbalanced genetic make-up, fully silencing the 18q22 trisomy and at least in part the Xq27 monosomy. The chromosomal abnormality observed in this family supports the presence of a DOR susceptibility locus in the distal Xq region and targets the POF1 region for further investigation.

A family with Xq22.3q25 interstitial deletion and normal ovarian function

OBJECTIVE

To investigate genomic changes in a family with deletion of X chromosome q22.3-q25 associated with normal constitutional and reproductive phenotypes.

DESIGN

Case report.

SETTING

Academic district hospital genetic laboratory.

PATIENT(S)

A family incidentally found to have deletion of X chromosome q22.3-q25.

INTERVENTION(S)

Cytogenetic analysis and array-based comparative genomic hybridization for amniotic fluid and peripheral blood lymphocyte of family members.

MAIN OUTCOME MEASURE(S)

Ovarian function and menstrual cycles.

RESULT(S)

The proband and two daughters showed deletion of Xq22.3q25. This region spans 17.4 Mb and contains 121 genes.

CONCLUSION(S)

Female subjects with deletion of Xq22.3q25 may present with normal constitutional and reproductive phenotypes.

Allelic reduction of Dlx5 and Dlx6 results in early follicular depletion: a new mouse model of primary ovarian insufficiency

Primary ovarian insufficiency (POI) is characterized by the loss of ovarian function before the age of 40 in humans. Although most cases of POI are idiopathic, many are familial, underlying a genetic origin of the disease. Mutations in genes involved in the control of steroidogenesis, such as NR5A1 (SF-1, Steroidogenic Factor 1), CYP17, CYP19A1 (aromatase), StAR (Steroidogenic Acute Regulatory), and the forkhead transcription factor FOXL2 have been associated with different forms of POI. In males, the homeobox transcription factors Dlx5 and Dlx6 are involved in the control of steroidogenesis through the activation of GATA4-induced-StAR transcription. Here, we analyze the potential involvement of Dlx5 and Dlx6 in female reproduction. To this end, we make use of an existing mouse model in which Dlx5 and Dlx6 are simultaneously disrupted. We show that: (i) allelic reduction of Dlx5 and Dlx6 in the mouse results in a POI-like phenotype, characterized by reduced fertility and early follicular exhaustion; (ii) in granulosa cell lines, a reciprocal regulation exists between Dlx5 and Foxl2; (iii) in the mouse ovary, allelic reduction of Dlx5/6 results in the upregulation of Foxl2. We propose that the mutual regulation between Dlx5/6 and Foxl2 and their opposite effects on StAR expression might contribute to determine the homeostatic control of steroidogenesis within the ovary. Dysregulation of this homeostatic control would result in abnormal follicular maturation and reduced fertility. Our results bring new elements to our conceptual model of follicle maturation and maintenance and provide new potential genetic targets for cases of familial POI.

Similar phenotype characteristics comparing familial and sporadic premature ovarian failure

OBJECTIVE

Premature ovarian failure (POF) is characterized by secondary amenorrhea before the age of 40 years, along with repeated increased follicle-stimulating hormone and low estrogen concentrations. POF is considered a complex genetic disease with a familial presentation in 12% to 50% of cases. POF may originate from different genes and various gene-environment interactions. The aim of this study was to identify possible differences in phenotype comparing women with familial and women with sporadic POF.

METHODS

A multicenter study was initiated in the Netherlands using standardized phenotyping. For each woman, medical history, menstrual cycle, and fertility and smoking status were assessed and a standardized examination was performed. Based on a detailed three-generation family history, women were identified as having either familial (defined as having at least one relative with POF) or sporadic POF.

RESULTS

A total of 58 familial cases and 142 sporadic cases of POF were identified. Maternal age at menopause was significantly lower in the women with familial compared with the women with sporadic POF (41.0 +/- 7.5 and 49.7 +/- 2.6 y, respectively; P < 0.001). Sex hormone-binding globulin concentration was significantly higher in the women with familial than in the women with sporadic POF (73.6 +/- 37.1 and 55.2 +/- 26.9 nmol/L, respectively; P = 0.002). All other characteristics, such as parity, bone mineral density, and serum follicle-stimulating hormone and lipid levels were similar, as was the incidence of autoimmunity and cytogenetic abnormalities.

CONCLUSIONS

Familial and sporadic POF do not differ in phenotype except for maternal menopause age and sex hormone-binding globulin concentration. Future studies are needed to unravel the genotype-phenotype interactions in POF.

Analysis of X chromosome genomic DNA sequence copy number variation associated with premature ovarian failure (POF)

BACKGROUND

Premature ovarian failure (POF) is a heterogeneous disease defined as amenorrhoea for >6 months before age 40, with an FSH serum level >40 mIU/ml (menopausal levels). While there is a strong genetic association with POF, familial studies have also indicated that idiopathic POF may also be genetically linked. Conventional cytogenetic analyses have identified regions of the X chromosome that are strongly associated with ovarian function, as well as several POF candidate genes. Cryptic chromosome abnormalities that have been missed might be detected by array comparative genomic hybridization.

METHODS

In this study, samples from 42 idiopathic POF patients were subjected to a complete end-to-end X/Y chromosome tiling path array to achieve a detailed copy number variation (CNV) analysis of X chromosome involvement in POF. The arrays also contained a 1 Mb autosomal tiling path as a reference control. Quantitative PCR for selected genes contained within the CNVs was used to confirm the majority of the changes detected. The expression pattern of some of these genes in human tissue RNA was examined by reverse transcription (RT)-PCR.

RESULTS

A number of CNVs were identified on both Xp and Xq, with several being shared among the POF cases. Some CNVs fall within known polymorphic CNV regions, and others span previously identified POF candidate regions and genes.

CONCLUSIONS

The new data reported in this study reveal further discrete X chromosome intervals not previously associated with the disease and therefore implicate new clusters of candidate genes. Further studies will be required to elucidate their involvement in POF.

Premature ovarian failure from current perspective

Premature ovarian failure (POF) is a syndrome characterised by amenorrhoea, hypoestrogenism and hypergonadotropinism before the age of 40. It is a disorder affecting approximately 1% of women <40 years, 1/1,000 women by the age of 30 and 1/10,000 women by the age of 20. POF is not merely an early menopause. Up to 50% of the patients with POF will have intermittent and unpredictable ovarian function which may persist for some years. Heterogeneity of POF is also reflected by the variety of possible causes, including autoimmunity, toxics, drugs, radiation, infectious as well as genetic defects. HRT remains the cornerstone of treatment and the only proven method of achieving pregnancy in these patients is by ovum donation.

Human studies on genetics of the age at natural menopause: a systematic review

BACKGROUND Timing of natural menopause has great implications for fertility and women's health. Age at natural menopause (ANM) is largely influenced by genetic factors. In the past decade, several genetic studies have been conducted to identify genes in ANM, which can help us unravel the biological pathways underlying this trait and the associated infertility and health risks. After providing an overview of the results of the genetic studies performed so far, we give recommendations for future studies in identifying genetic factors involved in determining the variation in timing of natural menopause. METHODS The electronic databases of Pubmed and Embase were systematically searched until September 2009 for genetic studies on ANM, using relevant keywords on the subject. Additional papers identified through hand search were also included. RESULTS Twenty-eight papers emerged from our literature search. A number of genetic regions and variants involved in several possible pathways underlying timing of ANM were identified, including two possible interesting regions (9q21.3 and chromosome 8 at 26 cM) in linkage analyses. Recent genome-wide association studies have identified two genomic regions (19q13.42 and 20p12.3), containing two promising candidate genes (BRKS1 and MCM). In the candidate gene association studies on ANM, very few consistent associations were found. CONCLUSION A number of genetic variants have been discovered in association with ANM, although the overall results have been rather disappointing. We have described possible new strategies for future genetic studies to identify more genetic loci involved in the variation in menopausal age.

Aetiology of premature ovarian failure

Premature ovarian failure (POF) is the occurrence of hypergonadotropic hypoestrogenic amenorrhoea in women under the age of 40 years. POF is idiopathic in 74–90% of cases but can be familial (4–33%) or sporadic. The known causes are: genetic aberrations; autoimmune ovarian damage; iatrogenic following surgery, radiotherapy or chemotherapy; environmental factors (viruses, toxins, etc.); and metabolic (galactosaemia, 17 OH deficiency, etc.) Genetic aberrations could involve the X chromosome (monosomy, trisomy or translocations) or be autosomal. Genetic mechanisms include reduced gene dosage and non-specific chromosome effect impairing meiosis, decreasing the pool of primordial follicles and increasing atresia due to apoptosis or failure of follicle maturation. The genes for POF-1 are localized to Xq 21.3–Xq27 and for POF-2 to Xq13.3–21.1. The FMR1 gene is responsible for the fragile X syndrome. It occurs due to CGG expansion of more than 55 repeats at the 5′UTR (Xq 27.3), which is associated with gene silence resulting in mental retardation in males, and POF in female carriers. Autoimmune ovarian damage is caused by the alteration of T-cell subsets and T-cell-mediated injury, increase of autoantibody producing B-cells and a low number of effector supressor/cytotoxic lymphocyte and a decrease of number and activity of natural killer cells. POF can be associated with other non-endocrine and endocrine diseases. The mutations of AIRE gene are responsible for polyendocrinopathies (APS I–III). As the cause of POF is unknown in the majority of cases and the number of women with POF is increasing, the primary goal of scientific groups worldwide should be focused on the study of the aetiology of POF.

Mother's menopausal age is associated with her daughter's early follicular phase urinary follicle-stimulating hormone level

OBJECTIVE

Early follicular phase follicle-stimulating hormone (FSH), a marker of ovarian reserve, has been used to predict time to menopause. A mother's age at menopause is related to her daughter's age at menopause, possibly because of genetic factors. In this study we sought to determine the relationship between maternal age at menopause and early follicular phase FSH of premenopausal daughters.

DESIGN

The Uterine Fibroid Study enrolled women randomly selected from a prepaid health plan, collected questionnaire data, and obtained early follicular phase urine samples for a subset of participants. For this secondary analysis, premenopausal women between the ages of 35 and 46 years, who provided a urine sample on cycle day 2, 3, 4, or 5 and their mother's age at natural menopause (n = 182) were selected from the original cohort. Initially bivariate analysis and subsequently regression modeling were performed to assess the independent relationship between maternal age at menopause and urinary creatinine-corrected FSH.

RESULTS

Unadjusted analyses and those adjusting for age (mean +/- SD, 40.5 +/- 3.2 y), smoking status (16% current smokers), and body mass index (26.8 +/- 6.9 kg/m) showed a significant association between maternal age at menopause and daughter's urinary FSH level (P < 0.04). Women whose mothers experienced earlier menopause had higher urinary FSH levels.

CONCLUSIONS

The significantly increased FSH values among women whose mothers experienced early menopause is consistent with previously reported associations between mother's and daughter's age of menopause. FSH, a marker of ovarian reserve, is influenced by both genetic and environmental factors. Future epidemiologic studies on FSH should include collection of information on maternal age at menopause.

Effect of natural early menopause on bone mineral density

OBJECTIVES

Early menopause (EM) is included among the risk factors for osteoporosis. Several studies have shown that women with early menopause have lower bone mineral density (BMD) than those with normal expected age of menopause. The aim of our cross-sectional study was to investigate the effects of time of menopause on vertebral bone mass in healthy postmenopausal women and to evaluate if early menopause is a risk factor for lower vertebral BMD.

METHOD

We studied 782 who had never received drugs acting on bone mass. The study population was divided into three groups: women with early, normal (NM), and late (LM) menopause. Our study population was further categorized in 5-year age segments between 45 and >75.

RESULTS

The three groups examined did not differ for age, age at menarche, body mass index (BMI), and vertebral BMD, while there were significant differences in age at menopause and years since menopause. Our study showed that women with EM presented significantly lower vertebral BMD than NM and LM in 50-54 age segments. Beyond 55 years, EM, NM, and LM women had no differences in lumbar BMD values.

CONCLUSIONS

In conclusion, controversial data demonstrated that the absolute amount of bone loss is greater after early menopause than after normal or late menopause, even if a slight effect of early menopause on bone mass cannot be excluded.

Spontaneous premature ovarian failure: management challenges

Premature ovarian failure (POF) generally describes a syndrome consisting of amenorrhea, sex steroid deficiency, and elevated/menopausal levels of ganadotropins in a woman aged more than two standard deviations below the mean age at menopause estimated for the reference population. Numerous questions relating to this condition remain unanswered, and several important management issues are yet to be addressed. The challenges posed by this important condition range from difficulties with nomenclature to the absence of standardized diagnostic criteria and management guidelines. In the present paper we discuss the management of spontaneous premature ovarian failure, highlight the challenging issues, review the current literature and propose a practical management outline based on our local practice. Women with POF have unique needs that require special attention. There is an urgent need for a more suitable terminology and evidence-based guidelines on which to establish the diagnosis and manage this difficult condition.

Incidence of reversible amenorrhea in women with breast cancer undergoing adjuvant anthracycline-based chemotherapy with or without docetaxel

BACKGROUND

To determine the incidence of reversible amenorrhea in women with breast cancer undergoing adjuvant anthracycline-based chemotherapy with or without docetaxel.

METHODS

We studied the incidence and duration of amenorrhea induced by two chemotherapy regimens: (i) 6 cycles of 5-fluorouracil 500 mg/m2, epirubicin 100 mg/m2 and cyclophosphamide 500 mg/m2 on day 1 every 3 weeks (6FEC) and (ii) 3 cycles of FEC 100 followed by 3 cycles of docetaxel 100 mg/m2 on day 1 every 3 weeks (3FEC/3D). Reversible amenorrhea was defined as recovery of regular menses and, where available (101 patients), premenopausal hormone values (luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol) in the year following the end of chemotherapy.

RESULTS

One hundred and fifty-four premenopausal patients were included: 84 treated with 6FEC and 70 with 3FEC/3D. The median age was 43.5 years (range: 28-58) in the 6FEC arm and 44 years (range: 29-53) in the 3FEC/3D arm. Seventy-eight percent of patients were treated in the context of the PACS 01 trial. The incidence of chemotherapy-induced amenorrhea at the end of chemotherapy was similar in the two groups: 93 % in the 6FEC arm and 92.8 % in the 3FEC/3D arm. However, in the year following the end of chemotherapy, more patients recovered menses in the 3FEC/3D arm than in the 6FEC arm: 35.5 % versus 23.7 % (p = 0.019). Among the 101 patients for whom hormone values were available, 43 % in the 3FEC/3D arm and 29 % in the 6FEC arm showed premenopausal levels one year after the end of chemotherapy (p < 0.01). In the 3FEC/3D group, there was a statistically significant advantage in disease-free survival (DFS) for patients who were still amenorrheic after one year, compared to patients who had recovered regular menses (p = 0.0017).

CONCLUSION

Our study suggests that 3FEC/3D treatment induces more reversible amenorrhea than 6FEC. The clinical relevance of these findings needs to be investigated further.

Genetic investigation of four meiotic genes in women with premature ovarian failure

OBJECTIVE

The goal of this study was to determine whether mutations of meiotic genes, such as disrupted meiotic cDNA (DMC1), MutS homolog (MSH4), MSH5, and S. cerevisiae homolog (SPO11), were associated with premature ovarian failure (POF).

DESIGN

Case-control study.

METHODS

Blood sampling, karyotype, hormonal dosage, ultrasound, and ovarian biopsy were carried out on most patients. However, the main outcome measure was the sequencing of genomic DNA from peripheral blood samples of 41 women with POF and 36 fertile women (controls).

RESULTS

A single heterozygous missense mutation, substitution of a cytosine residue with thymidine in exon 2 of MSH5, was found in two Caucasian women in whom POF developed at 18 and 36 years of age. This mutation resulted in replacement of a non-polar amino acid (proline) with a polar amino acid (serine) at position 29 (P29S). Neither 36 control women nor 39 other patients with POF possessed this genetic perturbation. Another POF patient of African origin showed a homozygous nucleotide change in the tenth of DMC1 gene that led to an alteration of the amino acid composition of the protein (M200V).

CONCLUSIONS

The symptoms of infertility observed in the DMC1 homozygote mutation carrier and in both patients with a heterozygous substitution in exon 2 of the MSH5 gene provide indirect evidence of the role of genes involved in meiotic recombination in the regulation of ovarian function. MSH5 and DMC1 mutations may be one explanation for POF, albeit uncommon.

Gene analysis in patients with premature ovarian failure or gonadal dysgenesis: A preliminary study

OBJECTIVE

The aim of this study was to evaluate the presence of mutations in the coding region of the QM gene and fragile X in patients with premature ovarian failure and gonadal dysgenesis.

METHODS

After approval by the local Ethics Committee, blood samples, in EDTA, of 100 normally ovulating women, 23 with premature ovarian failure (POF) and 14 with gonadal dysgenesis 46XX, aged less than 40 years, were screened for mutation in the QM gene coding region. All patients with POF have 46, XX karyotype and serum levels of follicle-stimulating hormone (FSH) over 30 mIU/mL. In addition, all samples from patients with premature ovarian failure underwent analysis for fragile X.

RESULTS

The QM gene located at a hotspot region (Xq28) showed five points of mutations in a patient with premature ovarian failure. Four of them were able to change the amino acid sequence of the protein. None of our patients were diagnosed as having pre or mutant X fragile syndrome.

CONCLUSION

Our study suggests that Xq28 (QM gene) may be involved in ovary failure. However, further studies are needed to confirm this hypothesis.

Ovarian dysfunction and FMR1 alleles in a large Italian family with POF and FRAXA disorders: case report

Background

The association between premature ovarian failure (POF) and the FMR1 repeat number (41> CGG_n< 200) has been widely investigated. Current findings suggest that the risk estimation for POF can be calculated in the offspring of women with pre-mutated FMR1 alleles.

Case presentation

We describe the coexistence in a large Italian kindred of Fragile X syndrome and familial POF in females with ovarian dysfunctions who carried normal or expanded FMR1 alleles. Genetic analysis of the FMR1 gene in over three generations of females revealed that six carried pre-mutated alleles (61–200), of which two were also affected by POF. However a young woman, who presented a severe ovarian failure with early onset, carried normal FMR1 alleles (<40). The coexistence within the same family of two dysfunctional ovarian conditions, one FMR1-related and one not FMR1-related, suggests that the complexity of familial POF conditions is larger than expected.

Conclusion

Our case study represents a helpful observation and will provide familial cases with heterogeneous etiology that could be further studied when candidate genes in addition to the FMR1 premutation will be available.

Skewed X-chromosome inactivation is associated with primary but not secondary ovarian failure

Premature ovarian failure (POF) is the occurrence of menopause before the age of 40, and may present with either primary or secondary amenorrhea. Numerous cases of POF in women with X-chromosome deletions or translocations have been reported; thus, it is possible that smaller rearrangements undetectable by conventional cytogenetics may contribute to POF in some patients. In females with an abnormal X chromosome, cells with inactivation of the normal X may be selected against, causing skewed X-chromosome inactivation (XCI). We therefore assessed XCI by methylation sensitive restriction digestion and PCR amplification at the androgen receptor (AR) locus, in 4 primary and 55 secondary POF patients and 109 control women. In samples heterozygous at AR and therefore informative for the skewing assay, the frequency of skewed XCI among the women with secondary amenorrhea was identical to that in control women, with 4 out of 48 (8.3%) secondary ovarian failure patients and 8 out of 97 (8.2%) control women having > or =90% skewing. Notably, all three primary amenorrhea patients that were informative at AR had skewed XCI > or =90% (P = 0.001 vs. control women; Fisher's exact test). To investigate whether X-chromosome copy number alterations were responsible, DNA from selected patients with skewed XCI was examined by high resolution DNA microarray, however no potential regions of DNA addition or deletion were confirmed by FISH or PCR. X-chromosome abnormalities undetectable by array, or reduced follicular pool due to an early trisomic rescue event, may explain the skewed XCI observed in POF patients presenting with primary amenorrhea.

Disruption of POF1B binding to nonmuscle actin filaments is associated with premature ovarian failure

Premature ovarian failure (POF) is characterized by elevated gonadotropins and amenorrhea in women aged <40 years. In a Lebanese family with five sisters who received the diagnosis of POF, we established linkage to the long arm of the X chromosome (between Xq21.1 and Xq21.3.3), using whole-genome SNP typing and homozygosity-by-descent mapping. By sequencing one candidate gene within that region, POF1B, we identified a point mutation localized in exon 10. This substitution of a nucleotide (G-->A), at position 1123, results in an arginine-->glutamine mutation of the protein sequence at position 329 (mutation R329Q). All the affected family members were homozygous for the mutation, whereas the unaffected members were heterozygous. Because POF1B shares high homology with the tail portion of the human myosin, we assessed the ability of both wild-type and mutant POF1B proteins to bind nonmuscle actin filaments in vitro. We found that the capacity of the mutant protein to bind nonmuscle actin filaments was diminished fourfold compared with the wild type, suggesting a function of POF1B in germ-cell division. Our study suggests that a homozygous point mutation in POF1B influences the pathogenesis of POF by altering POF1B binding to nonmuscle actin filaments.

Investigation of the human stem cell factor KIT ligand gene, KITLG, in women with 46,XX spontaneous premature ovarian failure

OBJECTIVE

To investigate mutations in the human KIT ligand gene (KITLG) gene as a mechanism of 46,XX spontaneous premature ovarian failure. The human KIT ligand gene, known also as human stem cell factor, is the ligand of the c-kit transmembrane tyrosine kinase receptor (KIT). This ligand-receptor interaction is known to play important roles in mouse germ cell migration and proliferation.

DESIGN

Cross-sectional study.

SETTING

Clinical research center.

PATIENT(S)

Forty women with 46,XX spontaneous premature ovarian failure.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Single-stranded conformational polymorphism analysis and DNA sequencing.

RESULT(S)

We found one nucleotide change of the KITLG coding region (811G-->T) that led to an alteration of the amino acid composition of the KITLG protein in one Caucasian patient (Asp210Tyr). However, we found the same alteration in two normal control Caucasian samples. Three nucleotide substitutions were found in the noncoding exon of KITLG (exon 10). We also identified two intronic polymorphisms. Thus, we did not identify a single significant mutation in the coding region of the KITLG gene in any of 40 patients (upper 95% confidence limit is 7.2%).

CONCLUSION(S)

Mutations in the coding regions of the KITLG gene appear not to be a common cause of 46,XX spontaneous premature ovarian failure in North American women.

Efficiency of equilibrium cooling and vitrification procedures for the cryopreservation of ovarian tissue: comparative analysis between human and animal models

OBJECTIVE

To compare the efficiency of equilibrium cooling and vitrification for cryopreservation of human ovarian tissue and to determine the best experimental model for developing new protocols.

DESIGN

Experimental prospective study.

SETTING

An academic research environment.

PATIENT(S) AND ANIMAL(S)

Human ovarian biopsy specimens were obtained from three women undergoing operative laparoscopy for ovarian cyst enucleation. Adult cow and pig ovaries, collected at the abattoir.

INTERVENTION(S)

Ovarian tissue fragments of three individuals for each species were cryopreserved by using two protocols, either for equilibrium cooling or vitrification.

MAIN OUTCOME MEASURE(S)

Comparison between fresh and cryopreserved tissue of primordial, primary, and secondary follicle morphology, graded in three classes.

RESULT(S)

Human and bovine follicles responded in the same way to the two equilibrium cooling protocols, whereas pig tissue was more cryoresistant. Both vitrification protocols caused extensive damage to the tissue of all species. Human tissue showed a response to vitrification that was different from that of both animal species.

CONCLUSION(S)

Bovine is a good animal model for the development of human ovarian tissue cryopreservation protocols by equilibrium cooling procedures. Vitrification is less efficient than equilibrium cooling, and at present, neither bovine nor pig can be considered relevant animal models for human tissue.

Premature ovarian failure and pregnancy

SETTING

A case study of a woman with presumed premature menopause is presented.

RESULTS

After more than 4 years of premature menopause judged by subjective symptoms, bleeding history, and postmenopausal levels of gonadotropins, a woman conceived spontaneously 2 months after the start of hormone replacement treatment (HRT). Previously, ovarian stimulation with clomifen citrate had failed. She delivered prematurely due to preeclampsia and intrauterine growth retardation.

CONCLUSIONS

Reviewing the literature finds that pregnancy is reported in woman with premature ovarian failure after the use of birth-control pills, HRT, ovarian stimulation, and in spontaneous cycles. Lack of oocyte donors and prohibition of the donor technique in some countries make other options valuable when optimal infertility treatment cannot be offered.

Heterozygosity mapping by quantitative fluorescent PCR reveals an interstitial deletion in Xq26.2-q28 associated with ovarian dysfunction

BACKGROUND

Deletions of Xq chromosome are reported for a number of familial conditions exhibiting premature ovarian failure (POF) and early menopause (EM).

METHODS AND RESULTS

We describe the inheritance of an interstitial deletion of the long arm of the X chromosome associated with either POF or EM in the same family. Cytogenetic studies and heterozygosity mapping by quantitative fluorescent PCR revealed a 46,X,del(X)(q26.2-q28) karyotype in a POF female, in her EM mother, and also in her aborted fetus with severe cardiopathy. Applying a microsatellite approach, we have narrowed the extension of an identical interstitial deletion located between DXS1187 and DXS1073. These data, in line with other mapped deletions, single out the proximal Xq28 as the region most frequently involved in ovarian failure. We also propose that other factors may influence the phenotypic effect of this alteration. Indeed, skewed X inactivation has been ascertained in EM and POF to be associated with different X haplotypes.

CONCLUSION

Our analysis indicates that Xq26.2-q28 deletion is responsible for gonad dysgenesis in a family with EM/POF. The dissimilar deletion penetrance may be due to epigenetic modifications of other X genes that can contribute to human reproduction, highlighting that ovarian failure should be considered as a multifactorial disease.

Genetic studies to identify genes underlying menopausal age

Menopausal age is important as a retrospective marker for ovarian senescence, an early menopausal age is associated with an increased risk of cardiovascular diseases and osteoporosis, whereas a later menopausal age has been associated with an increased risk of breast cancer. The worldwide average for age at natural menopause is approximately 51 years and is more or less normally distributed with a range roughly between 40 and 60 years. Environmental factors explain only a small part of the variance and it has been proposed that genetic factors are the main source of variation. Menopausal age may be considered a continuous complex trait. Complex traits are defined as traits that are influenced by both multiple genetic and environmental factors. A category of complex traits comprises those that are measured on a continuous scale. The genomic loci that make up the genetic component are called 'quantitative trait loci' or QTLs. The first linkage study on menopausal age suggests that the involvement of the X-chromosome may not be limited to premature ovarian failure (POF), but may influence the broader spectrum of menopausal age. A potentially new locus for variation in menopausal age was allocated to chromosome 9. Further studies need to identify new candidate genes to help unravel the pathophysiology of menopausal age. It is becoming increasingly clear that, in any speciality, it should be acknowledged that genetic factors are involved in many traits and that uncovering these factors may provide insight into pathogenesis and ultimately advance prevention and treatment of disease. In this review we discuss methods and basic principles of gene finding for such traits, exemplified by menopausal age as phenotype. Furthermore, we give an overview of the state of the art of candidate gene studies and linkage studies.

Poland's syndrome and premature ovarian failure

A 19-year-old female with Poland's Syndrome with associated left amastia, scoliosis, and left Sprengel deformity developed secondary amenorrhea from premature ovarian failure. Her menarche was at 13 years of age, and periods were regular and monthly until 15 years of age when her periods suddenly stopped. Her hormonal evaluation was significant for elevated FSH (46.5 mIU/ml) and LH (28.5 mIU/ml), and low estradiol (23 pg/ml). Anti-ovarian antibody level was less than 2 units (normal < 4 units). Her chromosomes were 46XX, by both standard karyotype and by fluorescence in situ hybridization. On transabdominal and transvaginal ultrasonography, ovaries were not visualized, the uterus was of normal size and anteverted and both kidneys were normal. The patient began hormone replacement therapy with conjugated estrogen (Premarin) 0.625 mg po daily and progestin (Provera) 5 mg on days 20 to 25. Because of menopausal symptoms, she was switched to a combination oral contraceptive (OC) with 20 mcg ethinyl estradiol that was eventually increased to 30 mcg. Her menopausal symptoms (hot flashes and sweating) improved on the continuous 30 mcg ethinyl estradiol combination OC. Following a comprehensive review of the literature, this is the first reported case of Poland's Syndrome associated with premature ovarian failure; however, this association may be coincidental.

Age at natural menopause is not linked with the follicle-stimulating hormone receptor region: a sib-pair study

OBJECTIVE

Studies have shown that age at natural menopause is heritable. Mutations in the FSH-receptor have been identified in women with premature ovarian failure (POF) and the FSH-receptor gene may, therefore, be considered a candidate gene for (early) menopausal age. This study investigates whether there is linkage between genetic markers in the FSH-receptor region and (early) age at menopause using a sib-pair design.

DESIGN

Sib-pair based linkage analysis.

SETTING

Sister pairs and their first-degree family members from The Netherlands.

PATIENT(S)

The inclusion criteria for a family were natural menopause in upper or lower tail of the distribution of menopausal age in at least two sisters. A total of 126 families with at least one sib-pair were included in this study. Six polymorphic markers encompassing the FSH-receptor gene were genotyped.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Single point and multipoint logarithm of the odds (LOD) scores.

RESULT(S)

None of the markers showed evidence in favor of linkage with overall age at natural menopause or early age at natural menopause.

CONCLUSION(S)

Possibly, age at natural menopause in the more or less normal range is not part of the spectrum of phenotypes determined by mutations in the FSH-receptor gene. Alternatively, our results might be explained by genetic heterogeneity in the left tail of the distribution of menopausal age. This can limit the chance of finding a genetic locus, especially if this factor has a modest contribution to the phenotype.

Linkage analysis of extremely discordant and concordant sibling pairs identifies quantitative trait loci influencing variation in human menopausal age

Age at natural menopause may be used as parameter for evaluating the rate of ovarian aging. Environmental factors determine only a small part of the large variation in menopausal age. Studies have shown that genetic factors are likely to be involved in variation in menopausal age. To identify quantitative-trait loci for this trait, we performed a genomewide linkage study with age at natural menopause as a continuous quantitative phenotype in Dutch sister pairs, through use of a selective sampling scheme. A total of 165 families were ascertained using extreme selected sampling and were genotyped for 417 markers. Data were analyzed by Haseman-Elston regression and by an adjusted variance-components analysis. Subgroup analyses for early and late menopausal age were conducted by Haseman-Elston regression. In the adjusted variance-components analysis, 12 chromosomes had a LOD score of > or =1.0. Two chromosomal regions showed suggestive linkage: 9q21.3 (LOD score 2.6) and Xp21.3 (LOD score 3.1). Haseman-Elston regression showed rather similar locations of the peaks but yielded lower LOD scores. A permutation test to obtain empirical P values resulted in a significant peak on the X chromosome. To our knowledge, this is the first study to attempt to identify loci responsible for variability in menopausal age and in which several chromosomal regions were identified with suggestive and significant linkage. Although the finding of the region on the X chromosome comes as no surprise, because of its widespread involvement in premature ovarian failure, the definition of which particular gene is involved is of great interest. The region on chromosome 9 deserves further consideration. Both findings require independent confirmation.

Diagnostic role of inhibin B in resistant ovary syndrome associated with secondary amenorrhea

To report two rare cases of gonadotropin-resistant ovary syndrome associated with secondary amenorrhea and normal levels of inhibin B. Case report. Two university teaching hospitals. Two women presenting with secondary amenorrhea and infertility. The control group for the inhibin B levels consisted of 30 cycling women of reproductive age. Medical history, physical examination, laboratory data, histologic findings, and IVF results. Diagnosis and treatment of resistant ovary syndrome. Case 1 was a 25-year-old woman with secondary amenorrhea and primary infertility. She had high serum levels of FSH and LH, low E(2) levels, and normal inhibin B levels (62 pg/mL). Karyotype was 46,XX, and ovarian biopsy showed primordial follicles with oocytes. Administration of GnRH analogue with hMG for 15 days did not affect E(2) levels. She had a successful pregnancy with IVF using donor oocytes. Case 2 was a 24-year-old woman with secondary amenorrhea. She had elevated serum levels of FSH and LH, low E(2) levels, and normal inhibin B levels (57 pg/mL). Karyotype was 46,XX and ovarian biopsy showed primordial follicles. Administration of GnRH analogue with hMG for 12 days did not affect E(2) levels. Both women were given estrogen-progestin replacement therapy. Inhibin B has a diagnostic role in women with gonadotropin-resistant ovary syndrome associated with secondary amenorrhea. A review of the literature confirms the uniqueness of the diagnostic role of inhibin B in these cases.

Sex-specific gene expression during meiotic prophase I: Xlr (X linked, lymphocyte regulated), not its male homologue Xmr (Xlr related, meiosis regulated), is expressed in mouse oocytes

The Xmr (Xlr related, meiosis regulated) gene product is abundantly expressed in primary spermatocytes and is notably associated with nonrecombining segments of sex chromosomes in the XY body. Here we determined whether Xmr was expressed in meiotic oocytes. This was done by reverse transcription-polymerase chain reaction and cDNA sequencing, Western blot analysis, and immunocytochemistry. Unexpectedly, no Xmr message was detected in mouse fetal oocytes. Instead, Xlr (X linked, lymphocyte regulated), a closely related gene expressed in fetal thymus cells at the time of antigen-receptor gene rearrangement, was expressed in oocytes throughout meiotic prophase I. These findings indicate a sex-specific expression of two closely related members of the Xlr gene family during meiotic prophase I. The XLR protein may provide a useful marker for studies on chromatin condensation or DNA recombination in oocytes. In addition, because of the localization of the Xlr sequence family on the mouse X chromosome, the human equivalent of Xlr is a candidate gene for premature ovarian failure.

Chemotherapy-induced amenorrhea and fertility in women undergoing adjuvant treatment for breast cancer

BACKGROUND

The majority of women diagnosed with early-stage breast cancer have an excellent long-term prognosis, but many will undergo temporary or permanent chemotherapy-induced amenorrhea.

METHODS

While breast cancer is more common in older women, about 1 in 200 women under the age of 40 is at risk to develop breast cancer. Many of these women benefit from chemotherapy but are afraid to risk the opportunity to bear children. The authors review the current studies on the impact of adjuvant chemotherapy on amenorrhea and fertility in women with breast cancer.

RESULTS

The likelihood of amenorrhea is based on the specific adjuvant chemotherapy regimen administered and the age of the patient. Future childbirth is a viable option for women treated for breast cancer at an early stage. While the use of tamoxifen as a hormonal therapy in premenopausal breast cancer is now the standard of care, no conclusive data confirm the benefit of GnRH agonists in adjuvant therapy after treatment with chemotherapy followed by tamoxifen.

CONCLUSIONS

As more women over the age of 35 consider pregnancy, fertility issues are becoming important areas of investigation for the adjuvant treatment of breast cancer. Whether chemotherapy-induced amenorrhea has a prognostic effect remains unclear, and further studies are warranted.

Genes and translocations involved in POF

Changes at a single autosomal locus and many X-linked loci have been implicated in women with gonadal dysgenesis [premature ovarian failure (POF) with deficits in ovarian follicles]. For the chromosome 3 locus, a forkhead transcription factor gene (FOXL2) has been identified, in which lesions result in decreased follicles by haploinsufficiency. In contrast, sporadic X; autosomal translocations are distributed at many points on the X, but concentrate in a critical region on Xq. The association of the breakpoints with genes involved in ovarian function is thus far weak (in four analyzed cases) and has not been related to pathology in other POF patients. While many more translocations can be analyzed in detail as the human genome sequence is refined, it remains possible that translocations like X monosomy (Turner syndrome) lead to POF not by interrupting specific genes important in ovarian development, but by causing aberrations in pairing or X-inactivation during folliculogenesis. It is noted that the critical region has unusual features, neighboring the X-inactivation center and including an 18 Mb region of very low recombination. These suggest that chromosome dynamics in the region may be sensitive to structural changes, and when modified by translocations might provoke apoptosis at meiotic checkpoints. Choices among models for the etiology of POF should be feasible based on studies of ovarian follicle development and attrition in mouse models. Studies would prominently include gene expression profiling of developmental-specific pathways in nascent ovaries with controlled levels of Foxl2 and interacting proteins, or with defined changes in the X chromosome.

Does functional depletion of stem cells drive aging?

The regenerative power of stem cells has raised issues about their relation to aging. We focus on the question of whether a decline in the function of stem cells may itself be a significant feature of aging. The question is implicitly two-fold: does functional depletion of stem cells affect the accumulation of aging-related deficits, and--whether or not depletion is significant--can activation of stem cells alleviate deficits? Two types of system are considered: 1) the exhaustible pool of ovarian follicles. The depletion of follicles leads to the aging-related phenomenon of menopause; and 2) the reserve of hematopoietic stem cells. Substantial numbers are sustained throughout life, but in mouse models, endogenous replicative activity has been shown to decline sharply with age. We discuss the possible implications of these observations for the rate of aging and the prospects for intervention.

The putative forkhead transcription factor FOXL2 is mutated in blepharophimosis/ptosis/epicanthus inversus syndrome

In type I blepharophimosis/ptosis/epicanthus inversus syndrome (BPES), eyelid abnormalities are associated with ovarian failure. Type II BPES shows only the eyelid defects, but both types map to chromosome 3q23. We have positionally cloned a novel, putative winged helix/forkhead transcription factor gene, FOXL2, that is mutated to produce truncated proteins in type I families and larger proteins in type II. Consistent with an involvement in those tissues, FOXL2 is selectively expressed in the mesenchyme of developing mouse eyelids and in adult ovarian follicles; in adult humans, it appears predominantly in the ovary. FOXL2 represents a candidate gene for the polled/intersex syndrome XX sex-reversal goat.