Family-based analysis of susceptibility loci for polycystic ovary syndrome on chromosome 2p16.3, 2p21 and 9q33.3

Susceptibility loci identified in Han Chinese influence genetic predisposition of PCOS in Indian women

BACKGROUND

Polycystic ovary syndrome (PCOS) is a multifactorial disorder characterized by a broad spectrum of reproductive and metabolic perturbations, necessitating early timely diagnosis and management. PCOS is a multigenic disorder and ample evidence from family based, candidate gene and genome-wide association studies (GWAS) has implicated genetic factors in development and progression of PCOS. The first GWASs in Han Chinese population revealed prominent gene loci to be strong contenders in the etiopathogenesis of PCOS. However, different ethnic and geographical settings impact the genetic association pattern of PCOS.

METHODS AND RESULTS

In the current case-control replication study, we have genotyped previously identified polymorphisms viz. rs2479106 and rs10818854 of DENND1A and rs13405728 of LHCGR, rs4385527 and rs3802457 of c9orf3, rs705702 of RAB5B and rs1894116 of YAP1 in control (N = 247) and PCOS (N = 504) women by Sanger sequencing, and their association with PCOS susceptibility and its related traits was investigated. We found significant association of rs4385527 of c9orf3 and rs1894116 of YAP1 with decreased and increased PCOS susceptibility respectively in non-hyperandrogenic women. Trend towards association was also noted for rs2479106 of DENND1A and rs705702 of RAB5B. Additionally, polymorphisms also showed association with metabolic and androgen related traits in both controls and hyper- and non-hyperandrogenic women with PCOS.

CONCLUSIONS

Thus, this study shows that some, but not all polymorphisms previously identified in Han Chinese women, could contribute to the genetic pathophysiology of PCOS in Indian women, accentuating essentiality of conducting replication studies to elucidate the genetic predisposition profile of PCOS.

Assessment of THADA gene polymorphisms in a sample of Colombian women with polycystic ovary syndrome: A pilot study

Polycystic ovary syndrome (PCOS) is a multifactorial and polygenic endocrine-metabolic disorder in women of reproductive age. SNPs in the THADA gene have been identified as PCOS risk loci. In this study, we evaluated the frequency of five polymorphisms in a sample of Colombian women with PCOS, and their association with clinical and endocrine-metabolic parameters. Forty-nine women with PCOS and forty-nine healthy women were included. Allelic discrimination was performed in the THADA gene by iPLEX and the MassARRAY system (Agena Bioscience). Haploview software was conducted to analyze the linkage disequilibrium (LD) and haplotypes of polymorphisms. There was an association between the genotypes TT of rs12468394, CC + AA of rs12468394, and GG of rs6544661 and an increase in the levels of free testosterone. The CC + AA of rs12468394 genotype also was associated with an increase of androstenedione levels. THADA gene SNPs were not associated with PCOS risk. There was very strong LD among the SNPs. No significant differences in the frequency of haplotypes between groups were observed. The statistical power of this analysis is low because of the small number of samples analyzed. Additional studies involving large populations of Colombian women with PCOS are needed to verify the role of the THADA gene in this disorder.

Evidence-based hormonal, mutational, and endocrine-disrupting chemical-induced zebrafish as an alternative model to study PCOS condition similar to mammalian PCOS model

Polycystic ovarian syndrome (PCOS) causes swollen ovaries in women at reproductive age due to hormonal disorder with small cysts on the outer edges. The cause of the disorder is still yet to be found. Multiple factors have increased PCOS prevalence, hyperandrogenism, oxidative stress, inflammation, and insulin resistance. Various animal PCOS models have been developed to imitate the pathophysiology of PCOS in humans. Zebrafish is one of the most versatile animal experimental models because of the transparency of the embryos, small size, and rapid growth. The zebrafish similarity to higher vertebrates made it a useful non-mammalian model for PCOS drug testing and screening. This review provides an insight into the usage of zebrafish, a non-mammalian model for PCOS, as an opportunity for evaluating future initiatives in such a research domain.

Thada Is Dispensable for Female Fertility in Mice

Genome-wide association studies (GWAS) have identified THADA as one of the susceptibility genes for polycystic ovary syndrome (PCOS). Single nucleotide polymorphisms (SNPs) in the THADA gene showed significant over-transmission in PCOS and strong correlations with testosterone level. However, there was insufficient evidence to verify the effect of THADA in vivo on female reproductive system. In this study, we investigated the impacts of Thada ablation on ovarian function and reproductive outcomes with knockout (KO) mice. The results showed that the Thada deletion was insufficient to affect ovarian folliculogenesis, steroidogenesis, and female fertility. Additionally, we stressed the mice with high-fat-high-sugar diet (HFHS). In this case, the KO mice still merely had a negligible impact on ovarian function. These findings indicated that Thada deficiency was dispensable for female fertility in mice, which enriched our knowledge about in vivo functions of PCOS susceptibility genes.

Pathophysiologic Mechanisms of Insulin Secretion and Signaling-Related Genes in Etiology of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrinopathy in women. PCOS is characterized by anovulation, hyperandrogenism, polycystic ovaries, insulin resistance, and obesity. Despite the finding that the genetic origin of PCOS is well demonstrated in previous twin and familial clustering studies, genes and factors that can exactly explain the PCOS pathophysiology are not known. Objective(s). In this review, we attempted to identify genes related to secretion and signaling of insulin aspects of PCOS and their physiological functions in order to explain the pathways that are regulated by these genes which can be a prominent function in PCOS predisposition. Materials and Methods. For this purpose, published articles and reviews dealing with genetic evaluation of PCOS in women from peer-reviewed journals in PubMed and Google Scholar databases were included in this review. Results. The genomic investigations in women of different populations identified many candidate genes and loci that are associated with PCOS. The most important of them are INSR, IRS1-2, MTNR1A, MTNR1B, THADA, PPAR-γ2, ADIPOQ, and CAPN10. These are mainly associated with metabolic aspects of PCOS. Conclusions. In this review, we proposed that each of these genes may interrupt specific physiological pathways by affecting them and contribute to PCOS initiation. It is clear that the role of genes involved in insulin secretion and signaling is more critical than other pathways.

Pilot study on evaluation and determination of the prevalence of Polycystic Ovarian Syndrome (PCOS) associated gene markers in the South Indian population

BACKGROUND

Polycystic ovarian syndrome (PCOS) is typically characterized by a spectrum of manifestations that include menstrual irregularities, anovulation, cysts, hyperandrogenic features like hirsutism, acne, alopecia, and various metabolic complications. The pathology of PCOS is complex and several mechanisms have been potentially involved in the genetic abnormalities/dysfunctions. Hence, the present study aims to examine the prevalence and association of polymorphisms in candidate genes (thyroid adenoma-associated gene [THADA], luteinizing hormone and human chorionic gonadotropin receptor [LHCGR], DENN domain containing 1A [DENND1A], follicle-stimulating hormone receptor [FSHR], Connexin37 [CX37], angiotensin-converting enzyme [ACE], insulin receptor [INSR] and calpain 10 [CAPN10]) in PCOS patients of the South Indian regional population.

METHODS

The study group included 20 PCOS cases and 10 controls, whose deoxyribonucleic acid (DNA) were genotyped by the polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism (RFLP), and PCR product sequencing to determine the prevalence of the DENND1A (rs10818854), LHCGR (rs13405728), FSHR (rs2349415), THADA (rs13429458), CX37 (rs1764391), ACE (rs1799752), INSR (rs1799817), and CAPN10 (rs2975760) polymorphisms. Clinical examinations including anthropometric measurements, biochemical investigations relevant to glucose metabolism, and hormones were measured.

RESULTS

A significant difference was observed in the DENND1A (rs10818854) polymorphism between the control and PCOS patients (P = 0.001). The variants of LHCGR, FSHR, THADA, CX37, ACE, INSR, and CAPN10 were not statistically significant with PCOS. The body mass index (BMI) (P = 0.01), triglycerides (P = 0.01), and dehydroepiandrosterone sulfate (DHEAS) (P = 0.05) were significantly different between the PCOS patients and controls. Significant results were observed in rs1799817 single nucleotide polymorphisms (SNP) of INSR with elevated levels of triglycerides and rs10818854 of DENND1A, rs13429458 of THADA, rs2349415 of FSHR with the high levels of DHEAS.

CONCLUSION

In the study population, the presence of rs10818854 of DENND1A polymorphism may be associated with the risk of PCOS and high levels of DHEAS.

Replication study of THADA rs13429458 variant with PCOS susceptibility and its related traits in Indian women

AIM

The aetiopathogenesis of the multigenic multifactorial endocrinopathy, polycystic ovary syndrome (PCOS) has been explored using linkage, candidate gene and genome-wide association studies. Contradictory reports of replication studies attributed to phenotypic, ethnic and geographic variations are available. In this study, we investigated the association of Han Chinese GWAS polymorphism (rs13429458) in thyroid adenoma-associated gene (THADA) with PCOS susceptibility and its related traits in Indian women.

METHODS

We genotyped rs13429458 of THADA by direct sequencing and investigated its association with PCOS and its related traits in controls (N = 150) and PCOS women (N = 348). All women were extensively phenotyped in terms of anthropometric, hormonal and metabolic parameters. Association of polymorphism with PCOS risk and its related traits was carried out by regression analysis.

RESULTS

Genotypic and allele frequencies for rs13429458 were not different between controls and PCOS. Women with PCOS carrying variant allele showed significantly reduced fasting glucose levels, and decreased free and bioavailable testosterone and free androgen index.

CONCLUSION

To our knowledge, this is the first study to demonstrate that although this polymorphism does not alter PCOS susceptibility, it favorably impacts glucose metabolism and hyperandrogenism in Indian women with PCOS only. This study highlights that genetic predisposition markers for PCOS may differ with ethnicity and phenotypic variations.

Improving the sexual activity and reproduction of female zebrafish with high testosterone levels

High levels of testosterone cause clinical symptoms in female reproduction and possibly, alterations in sexuality. Yet, the underlying mechanisms remain to be examined. Here, we report a study that investigates the effects of testosterone in follicle development and sexual mating using zebrafish models. We developed an acute zebrafish model with high testosterone levels by exposing young female zebrafish to testosterone dissolved in swimming water. After given a high concentration of testosterone treatment (e.g., 100 ng/ml), the fish showed hallmark pathological symptoms similar to those displayed in patients with polycystic ovary syndrome (PCOS), such as follicular growth-arrest, rare ovulation, ovary enlargement, decrease in reproduction, and down regulation of the expression of some PCOS susceptible genes, such as Tox3. These fish are referred to as the PCOS fish. By monitoring mating-like swimming behaviors, we measured the sexual activity of PCOS zebrafish. In general, the PCOS fish showed no desire to interact with males. As a consequence, their mating rate was decreased as compared to control animals. The sexuality levels of PCOS fish, however, could be improved after short periods of rearing in conditions that lack of males. After only 3 days of rearing alone, the PCOS fish showed an increase in sexuality levels and displayed characteristic swimming patterns for mating. After 30 days of separation from males, not only the sexual activity, but also the mating rate was improved in the PCOS fish. Together, the data suggests that zebrafish can serve as a new type of research model to further develop strategies for the treatment of reproductive disorders, such as those related to PCOS.

PCOS-GWAS Susceptibility Variants in THADA, INSR, TOX3, and DENND1A Are Associated With Metabolic Syndrome or Insulin Resistance in Women With PCOS

Polycystic ovary syndrome is characterized by reproductive and metabolic disturbances throughout the female lifespan. Therefore, this study aimed to determine whether genome-wide association studies (GWAS)-identified risk variants for PCOS could confer risk of metabolic syndrome (MS) or insulin resistance (IR). Fifteen independent SNPs mapping to 11 GWAS loci genotyped in a total of 2,082 Han Chinese women independent of previous GWAS and phenotype-genotype correlations were assessed. The CC group for rs12478601 in THADA was associated with decreased rate of MS after adjustment for age (23.2 vs. 27%, P = 0.042, OR = 0.81). Using a dominant model, the GG+AG group for rs2059807 in INSR was associated with increased risk of MS after adjustment for age (26.8 vs. 22.5%, P = 0.023, OR = 1.27). The GG + GT group for rs4784165 in TOX3 was found to be associated with an increased rate of IR after adjustment for age and BMI(53.3 vs. 48.5%, P = 0.027, OR = 1.27). The GG+AG group for rs2479106 in DENND1A was associated with a decreased rate of IR (48.3 vs. 53.6%, adjusted P = 0.039, OR = 0.80). After exclusion of PCOS cases with a family history of diabetes, hypertension, or dyslipidemia, the phenotype-genotype correlations between the genes INSR and TOX3 and MS or IR were still significant (P < 0.05). Three SNPs (rs13429458 in THADA, rs10818854 in DENND1A, and rs2059807 in INSR) were significantly associated with IR; however, their association was not significant after adjustment for age and BMI. This genotype-phenotype study thus provides clues that THADA, INSR, TOX3, and DENND1A play a role in PCOS possibly through a metabolic disorder-related pathway.

Genotype based Risk Predictors for Polycystic Ovary Syndrome in Western Saudi Arabia

Polycystic ovary syndrome (PCOS) is the most common endocrine disease among premenopausal women. The genetic risk of PCOS in the Saudi population is still unclear. Therefore, it is of interest to study the genotype and allele frequency for six gene variants (THADA rs13429458, TOX3 rs4784165, FSHR rs2268361, YAP1 rs1894116, RAB5B rs705702, and HMGA2 rs2272046) in patients with PCOS in western Saudi population. The study included 95 PCOS patients and 94 normal ovulatory females as controls. Genotyping was performed using TaqMan™ real-time polymerase chain reaction assays. There was significant link between the THADA rs13429458 variant and PCOS. Homozygosity in allele A of the rs13429458 variant was correlated with hyperandrogenism (HA) risk. Homozygosity in the T allele of the FSHR rs2268361 variant was associated with normal levels of AMH among non-PCOS women. The THADA rs13429458 and TOX3 rs4784165 variants were significantly associated with the combined oligo/amenorrhea (OA) and polycystic ovarian morphology subgroups while the HMGA2 rs2272046 variant was significantly associated with the combined HA and OA subgroup. Thus, results show the genetic risk of the THADA rs13429458, TOX3 rs4784165, and HMGA2 rs2272046 variants on PCOS patients in the western Saudi population.

Association of Rs13405728, Rs12478601, and Rs2479106 single nucleotide polymorphisms and in vitro fertilization and embryo transfer efficacy in patients with polycystic ovarian syndrome: A case control genome-wide association study

Polycystic ovary syndrome (PCOS) is a common female endocrine disorder that has a detriment impact on female health. Herein, the study used a case-control analysis to sought to explore the association of rs13405728, rs12478601, and rs2479106 single nucleotide polymorphisms (SNPs) with in vitro fertilization and embryo transfer (IVF-ET) efficacy in treating PCOS. A total of 163 PCOS patients (52 cycles) were selected as the PCOS group and 171 patients with tubal factor infertility without PCOS (68 cycles) were selected as the control group. Polymerase chain reaction was used to amplify genome DNA and direct sequencing to detect SNPs. The LHCGR rs13405728, THADA rs12478601, and DENND1A rs2479106 genotypes were subsequently tested. Logistic regression analysis was conducted to analyze the risk factors influencing the occurrence of PCOS as well as those influencing the efficacy of IVF-ET. rs13405728, rs12478601, and family history of DM were influencing factors for the occurrence of PCOS. The rate of abortion and number of oocytes retrieved of patients with the THADA rs12478601 CC genotype increased but the rate of clinical gestation decreased. Patients with AG + GG genotype of the DENND1A rs2479106 had increased number of oocytes retrieved, rate of abortion and incidence of gestational DM. rs13405728, rs12478601, serum E₂ value as well as fertility rate were influencing factors for efficacy of IVF-ET. It was suggested that the TT genotype of LHCGR rs13405728, CC genotype of THADA rs12478601 and AG + GG genotype of DENND1A rs2479106 had poor outcomes of IVF-ET in treating PCOS.

The association of DENND1A gene polymorphisms and polycystic ovary syndrome risk: a systematic review and meta-analysis

PURPOSE

Polycystic ovary syndrome is heterogeneity disease, and the association with DEEND1A gene has been discussed incompatibly for a long time. We conducted a meta-analysis to evaluate the rs10818854, rs2479106, and rs10986105 polymorphism in DENND1A gene with PCOS susceptibility.

METHODS

Meta-analysis was performed for common allele versus rare allele using random effect model on published papers from January 1, 1980 to October 1, 2015. Subgroup analysis, sensitivity analysis and publication bias were also carried out ultimately. The combined odds ratio (OR) with 95 % confidence interval (95 % CI) was calculated to estimate the strength of the association.

RESULTS

The results showed that rs10818854 (OR = 1.36, 95 % CI 1.12-1.61) and rs10986105 (OR = 1.39, 95 % CI 1.20-1.58) polymorphism increased the risk of PCOS probably. A significant association was also found between rs2479106 mutation and Asian PCOS patients but not Europeans (OR = 1.32, 95 % CI 1.25-1.39; OR = 1.01, 95 % CI 0.97-1.05, respectively).

CONCLUSIONS

In conclusion, the DENND1A gene variant is likely to have influence on PCOS risk. Further studies are warranted to assess these associations in greater detail, especially in different populations and different subtype of PCOS patients.

Association of DENND1A Gene Polymorphisms with Polycystic Ovary Syndrome: A Meta-Analysis

OBJECTIVE

The rs2479106 and rs10818854 polymorphisms in the DENND1A gene have been reported to be extensively associated with risk of polycystic ovary syndrome (PCOS). However, the results from these studies remained inconclusive and conflicting. To detect a true association of rs2479106 and rs10818854 polymorphisms with PCOS risk, a single study may be underpowered, particularly for those studies with inadequate sample size. Therefore, we performed a meta-analysis of all available studies to explore this association.

METHODS

All studies published up to March 2015 on the association were identified by searching electronic databases PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure. Studies containing available genotype frequencies of those 2 polymorphisms were chosen, and the odds ratios and associated 95% confidence intervals were calculated using fixed- or random- effects models.

RESULTS

A total of 8 studies about s2479106 polymorphism (8185 cases and 28675 controls) and 5 studies about rs10818854 polymorphism (6638 cases and 27443 controls) met the inclusion criteria for the meta-analysis. Overall, significant increase of PCOS risk was found between DENND1A-rs10818854 and PCOS susceptibility. In addition, we also found an increased risk of PCOS in rs2479106 allele model, heterozygote variant genetic model, and dominant genetic model.

CONCLUSION

This meta-analysis suggested that rs2479106 and rs10818854 polymorphisms in the DENND1A gene were associated with increased risk of PCOS. To validate the association between these polymorphisms and PCOS susceptibility, further large and well-designed studies are needed.

Genetic determinants of polycystic ovary syndrome: progress and future directions

The field of the genetics of polycystic ovary syndrome (PCOS) has relatively recently moved into the era of genome-wide association studies. This has led to the discovery of 16 robust loci for PCOS. Some loci contain genes with clear roles in reproductive (LHCGR, FSHR, and FSHB) and metabolic (INSR and HMGA2) dysfunction in the syndrome. The next challenge facing the field is the identification of causal variants and genes and the role they play in PCOS pathophysiology. The potential for gene discovery to improve diagnosis and treatment of PCOS is promising, though there is much to be done in the field before the current findings can be translated to the clinic.

Effects of brain-derived neurotrophic factor on oocyte maturation and embryonic development in a rat model of polycystic ovary syndrome

Brain-derived neurotrophic factor (BDNF) is expressed extensively in the mammalian female reproductive system and has been implicated in the development of follicles and oocytes. However, BDNF expression patterns in the ovary and its effects on oocyte maturation and embryonic development in polycystic ovary syndrome (PCOS) have not been established. In the present study, we established a PCOS model by treating the rats with insulin and human chorionic gonadotropin (hCG). Rats treated with insulin + hCG had heavier bodyweight and ovarian weight, higher circulating concentrations of luteinising hormone (LH) and testosterone (T), and greater homeostatic model assessment of insulin resistance (HOMA-IR) values compared with control rats (P < 0.05). BDNF and its receptor tyrosine kinase type B (TrkB) were located in cyst walls, granulosa and theca cells, and BDNF protein levels were lower in ovaries of insulin + hCG-treated rats (P < 0.05). The rate of oocyte maturation and formation of blastocysts and morulae was greatest in rats treated with 5 ng mL–1 BDNF (P < 0.05) compared to other BDNF groups (1 and 10 ng mL–1) and the control. The control rats were also PCOS rats and were treated without BDNF. There were no significant differences in the rate of germinal vesicle breakdown (GVBD) and fertilisation among the various treatment groups (1, 5 and 10 ng mL–1) and the control group (P > 0.05). The results indicate that in vitro treatment with an appropriate concentration of BDNF not only promotes oocyte maturation, but also rescues embryonic development in rats treated with insulin + hCG as a model of PCOS.

Family-based analysis of eight susceptibility loci in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that is proposed to have a genetic basis. A recent genome-wide association study (GWAS) identified eight new risk loci that are independently associated with PCOS. To further validate the findings, a total of 321 case-parent trios (963 participants) who had a proband affected with PCOS were recruited for the family-based study. The transmission disequilibrium test (TDT) was used to analyze associations between PCOS and ten single nucleotide polymorphisms (SNPs) mapped to eight new susceptibility loci. Significant differences in transmission were observed for the SNPs rs2349415 (located in the FSHR gene, P = 0.0001) and rs3802457 (located in the C9orf3 gene, P = 0.0001), even after correction for multiple testing bias. The present data provides further evidence for an association between two susceptibility loci, 2p16.3 and 9q22.32, and PCOS. Follow-up functional studies on the FSHR and C9orf3 genes are required to understand their roles in PCOS development.

Follicle-stimulating hormone receptor (FSHR) alternative skipping of exon 2 or 3 affects ovarian response to FSH

Genes critical for fertility are highly conserved in mammals. Interspecies DNA sequence variation, resulting in amino acid substitutions and post-transcriptional modifications, including alternative splicing, are a result of evolution and speciation. The mammalian follicle-stimulating hormone receptor (FSHR) gene encodes distinct species-specific forms by alternative splicing. Skipping of exon 2 of the human FSHR was reported in women of North American origin and correlated with low response to ovarian stimulation with exogenous follicle-stimulating hormone (FSH). To determine whether this variant correlated with low response in women of different genetic backgrounds, we performed a blinded retrospective observational study in a Turkish cohort. Ovarian response was determined as low, intermediate or high according to retrieved oocyte numbers after classifying patients in four age groups (<35, 35-37, 38-40, >40). Cumulus cells collected from 96 women undergoing IVF/ICSI following controlled ovarian hyperstimulation revealed four alternatively spliced FSHR products in seven patients (8%): exon 2 deletion in four patients; exon 3 and exons 2 + 3 deletion in one patient each, and a retention of an intron 1 fragment in one patient. In all others (92%) splicing was intact. Alternative skipping of exons 2, 3 or 2 + 3 were exclusive to low responders and was independent of the use of agonist or antagonist. Interestingly, skipping of exon 3 occurs naturally in the ovaries of domestic cats--a good comparative model for human fertility. We tested the signaling potential of human and cat variants after transfection in HEK293 cells and FSH stimulation. None of the splicing variants initiated cAMP signaling despite high FSH doses, unlike full-length proteins. These data substantiate the occurrence of FSHR exon skipping in a subgroup of low responders and suggest that species-specific regulation of FSHR splicing plays diverse roles in mammalian ovarian function.

Polycystic ovary syndrome: current status and future perspective

Polycystic ovary syndrome (PCOS) is a widespread reproductive disorder that encompasses many associated health conditions and has an impact on various metabolic processes. PCOS is depicted by hyperandrogenism, polycystic ovaries, and anovulation. It increases the risk of insulin resistance (IR), type 2 diabetes, obesity, and cardiovascular disease. The etiology of the disease remains unclear, and the subjective phenotype makes a united diagnosis difficult among physicians. It seems to be a familial genetic syndrome caused by a combination of environmental and genetic factors. It can be linked with metabolic disorders in first-degree family members. PCOS is the cause of up to 30% of infertility in couples seeking treatment. Currently, there is no cure for PCOS. Despite the growing incidence of this syndrome, limited research has been done that encompasses the entirety of PCOS spectrum. In this review, the current status and possible future perspective will be discussed.

Genetic factors modulate the impact of pubertal androgen excess on insulin sensitivity and fertility

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of reproductive age women. The syndrome is caused by a combination of environmental influences and genetic predisposition. Despite extensive efforts, the heritable factors contributing to PCOS development are not fully understood. The objective of this study was to test the hypothesis that genetic background contributes to the development of a PCOS-like reproductive and metabolic phenotype in mice exposed to excess DHEA during the pubertal transition. We tested whether the PCOS phenotype would be more pronounced on the diabetes-prone C57BL/6 background than the previously used strain, BALB/cByJ. In addition, we examined strain-dependent upregulation of the expression of ovarian and extra-ovarian candidate genes implicated in human PCOS, genes containing known strain variants, and genes involved with steroidogenesis or insulin sensitivity. These studies show that there are significant strain-related differences in metabolic response to excess androgen exposure during puberty. Additionally, our results suggest the C57BL/6J strain provides a more robust and uniform experimental platform for PCOS research than the BALB/cByJ strain.

Replication study of RAD54B and GREB1 polymorphisms and risk of PCOS in Han Chinese

A previous genome-wide association study (GWAS) of polycystic ovary syndrome (PCOS) identified several susceptibility loci, with P-values about 10⁻⁵. In the present study, an independent cohort was used for a replication study to evaluate the association of RAD54B and GREB1 with polycystic ovary syndrome (PCOS) in the Han Chinese population. Four single-nucleotide polymorphisms (SNP), rs2930961 (RAD54B), rs12470971, rs11686574 and rs6740248 (GREB1), were genotyped in 1124 PCOS patients and 1067 healthy controls from the Han Chinese population. Real-time quantitative PCR by TaqMan-MGB probe assay was applied for genotyping. The allele and genotype frequencies of these four SNP were not significantly different in the replication cohort. However, the minor allele frequency of rs2930961 was significantly different in hyperandrogenism of PCOS. After meta-analysis by combining the results of these two studies, there was a non-significant trend for the association of rs2930961 (RAD54B) with PCOS. RAD54B and GREB1 gene polymorphisms may not be associated with PCOS in the Han Chinese population. Nevertheless, RAD54B may contribute to hyperandrogenism in PCOS patients.

Genetic association studies in female reproduction: from candidate-gene approaches to genome-wide mapping

Many genetic association studies have been performed to investigate disorders of female reproduction, such as polycystic ovary syndrome, premature ovarian failure and endometriosis. These disorders typically manifest heterogeneously, and their pathogeneses are influenced by polygenic and environmental factors. Researchers evaluating these genetic associations have chosen candidate genes related to hormone action, steroid biosynthesis, inflammatory cytokines and autoimmune factors. Several of these genes have yielded statistically significant associations with female reproductive disorders; however, few associations have been robust and reproducible. Whole-genome association studies generate more reliable and unbiased results and represent a breakthrough in genetic studies of female reproduction. Nevertheless, to date only a very small fraction of the overall heritability has been identified and so further studies are needed.

Diagnosis and treatment of polycystic ovarian syndrome in adolescents

PURPOSE OF REVIEW

To review what is understood about the pathophysiology of polycystic ovarian syndrome (PCOS), the diagnostic challenges of PCOS in adolescent women, associated risk factors, as well as the best evidence-based treatment options for adolescence.

RECENT FINDINGS

Diagnosing PCOS in adolescents requires a unique set of criteria for which no single marker currently exists. Adolescents at high risk for developing the syndrome are congenital virilization, low birth weight, premature pubarche, central precocious puberty, large for gestational age girls born to overweight mothers, obesity syndromes, insulin-resistant features, and girls born to parents with PCOS, central obesity, or diabetes in whom PCOS ought to be suspected when associated with irregular menses. Insulin, hyperandrogenemia, and adipocytokines are integral players in the pathophysiology of PCOS. PCOS may be an inheritable trait; however, no gene has yet been identified. Quality of life remains a concern for young women with PCOS. Lifestyle modifications geared to prevent long-term sequelae remain the first-line treatment in conjunction with oral contraceptive pills.

SUMMARY

Identifying PCOS in adolescents remains a diagnostic dilemma, but early intervention and treatment can improve long-term health.

Emerging concepts about prenatal genesis, aberrant metabolism and treatment paradigms in polycystic ovary syndrome

The interactive nature of the 8th Annual Meeting of the Androgen Excess and PCOS Society Annual Meeting in Munich, Germany (AEPCOS 2010) and subsequent exchanges between speakers led to emerging concepts in PCOS regarding its genesis, metabolic dysfunction, and clinical treatment of inflammation, metabolic dysfunction, anovulation and hirsutism. Transition of care in congenital adrenal hyperplasia from pediatric to adult providers emerged as a potential model for care transition involving PCOS adolescents.

Genome-wide association study identifies GYS2 as a novel genetic factor for polycystic ovary syndrome through obesity-related condition

To investigate the role of genetic predisposition in the pathogenesis of polycystic ovary syndrome (PCOS) in relation to obesity, we performed a genome-wide association study of PCOS in Koreans (n=1741). PCOS is a heterogeneous endocrinal disorder of uncertain etiology. Obesity is one of the well-known risk factors for PCOS. Genome-wide association study. Women with or without PCOS. A total of 1881 samples were genotyped using Illumina HumanOmni1 Quad v1 and processed by R packages. The PCOS patients were divided into two subgroups according to PCOS diagnostic criteria (Rotterdam and National Institutes of Health (NIH)). For PCOS-associated loci in the two definitions, we successfully confirmed significant associations of GYS2 for body mass index in the discovery stage. We further replicated pleiotropic associations of GYS2 in a childhood obesity study (n=482) and in a gestational diabetes study (n=1710), respectively. Our study provides a preliminary framework upon diverse genetic effects underlying PCOS in Korean women. A newly identified GYS2 gene as a predisposing factor of PCOS might expand understanding of the biological pathways in metabolic and endocrine regulation.

Variants in DENND1A and LHCGR are associated with endometrioid adenocarcinoma

OBJECTIVE

The aim of this study was to explore the polycystic ovary syndrome (PCOS) related single nucleotide polymorphisms (SNPs) rs13405728 (in gene LHCGR), rs13429458 (in gene THADA) and rs2479106 (in gene DENND1A) in women with endometrial carcinoma.

METHODS

We conducted a case-control study comprising 96 Han Chinese women with endometrial carcinoma, and 192 healthy controls. SNPs rs13405728, rs13429458 and rs2479106 were genotyped by polymerase chain reaction (PCR) and direct sequencing. The effects of body mass index (BMI) and age were evaluated using an unconditional logistic regression model adjusted for potential confounders.

RESULTS

The allele frequencies of SNPs rs2479106 and rs13405728 were significantly different (P<0.05) between endometrial carcinoma group and control group, and the difference was especially significant in the subgroup of endometrioid adenocarcinoma. Genotyping analysis showed that allele G in rs2479106 and allele A in rs13405728 could confer risk to endometrioid adenocarcinoma.

CONCLUSIONS

Our results suggest that SNPs rs2479106 in gene DENND1A and rs13405728 in gene LHCGR are associated with endometrioid adenocarcinoma.

Pharmacogenetics of follicle-stimulating hormone action

PURPOSE OF REVIEW

To review the current knowledge of genetic variants in the two genes affecting the individual responsiveness to follicle-stimulating hormone (FSH) action-the FSH beta-subunit (FSHB) and the FSH receptor (FSHR), as well as the pharmacogenetic ramifications of the findings.

RECENT FINDINGS

Four common variants in the FSHB and the FSHR genes were shown to exhibit significant effect on FSH action: linked FSHR variants Thr307Ala and Asn680Ser determining common receptor isoforms, and gene expression affecting polymorphisms FSHR -29G/A and FSHB -211G/T. In women, the FSHR Thr307Ala/Asn680Ser polymorphisms show consistent predictive value for estimating the most optimal recombinant FSH dosage in controlled ovarian hyperstimulation (COH). The same variants exhibit a potential for the pharmacogenetic assessment of the treatment of polycystic ovarian syndrome. The FSHR -29G/A variant was also shown to contribute to ovarian response to COH. Pilot studies have suggested the FSHB -211 TT homozygous oligozoospermic men with genetically determined low concentration of FSH, as potentially the best responders to FSH treatment; furthermore, modulation of this response by FSHR polymorphisms is possible.

SUMMARY

Genetic variants in FSHB and FSHR exhibit a potential for pharmacogenetic applications in selecting appropriate treatment options (timing and dosage) in male and female conditions requiring or benefiting from FSH therapy.

Association of polycystic ovary syndrome susceptibility single nucleotide polymorphism rs2479106 and PCOS in Caucasian patients with PCOS or hirsutism as referral diagnosis

CONTEXT

Polycystic ovary syndrome (PCOS) is the most common endocrine disease among premenopausal women. A recent study found association between three single nucleotide polymorphisms (SNPs) and PCOS in a cohort of Han Chinese women.

OBJECTIVE

To investigate the association between rs13405728 (LHCGR gene), rs13429458 (THADA gene) and rs2479106 (DENND1A gene), PCOS, hirsutism and metabolic and hormonal parameters in a well characterized cohort of Caucasian patients of Danish descendant with PCOS or hirsutism.

STUDY DESIGN

Patients underwent clinical examination, hormone analyses, oral glucose tolerance test and transvaginal ultrasound. Genetic variation was tested using allelic discrimination by real-time PCR.

PATIENTS

268 patients referred to The Department of Endocrinology, Odense University Hospital, Denmark with PCOS or hirsutism between 1997 and 2011. Two hundred and forty-eight healthy females were included as controls.

RESULTS

Genotype distributions and allele frequencies of rs13405728, rs13429458, and rs2479106 were comparable in patients and controls. The rs2479106 G allele was associated with a decreased PCOS susceptibility. None of the SNPs were associated with hirsutism or increased metabolic parameters.

CONCLUSIONS

The rs2479106 G allele was associated with decreased PCOS susceptibility, thus confirming previously reported findings of association between rs2479106 and PCOS. Metabolic and hormonal parameters were comparable between genotypes of rs13405728 and rs2479106.