Genetics of polycystic ovarian syndrome

Association of SNPs in the FK-506 binding protein (FKBP5) gene among Han Chinese women with polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in premenopausal women, whose etiology remains uncertain, although it is known to be highly heterogeneous and genetically complex. PCOS often presents with hyperandrogenism symptoms. The present study aimed to determine whether polymorphisms in the FK-506 binding protein 5 (FKBP5) gene (androgen target gene) are associated with an association for PCOS and hyperandrogenism.

Methods

This is a case–control study, and association analyses were conducted. A total of 13 single-nucleotide polymorphisms (SNPs) in the FKBP5 gene were evaluated in 775 PCOS patients who were diagnosed based on the Rotterdam Standard and 783 healthy Chinese Han women. Associations between FKBP5 SNPs and hormone levels were investigated. These 13 SNPs were genotyped using the Sequenom MassARRAY system, and an association analysis between the phenotype and alleles and genotypes were conducted.

Results

The genotype frequencies for the rs1360780 and rs3800373 SNPs differed significantly between the PCOS cases and healthy controls (p = 0.025, OR is 1.63 (1.05–2.53) and p = 0.029, OR is 1.59 (1.03–2.45) respectively under co-dominant model). Moreover, the genotype frequencies and genetic model analysis for the SNPs rs1360780, rs9470080, rs9296158, rs1043805 and rs7757037 differed significantly between the hyperandrogenism and non-hyperandrogenism groups of PCOS patients. The TT genotype of rs1360780, the TT genotype of rs9470080, the TT genotype of rs1043805 or the GG genotype of rs7705037 (ORs are 2.13 (1.03–4.39), 1.81 (1.03–3.17), 2.94 (1.32–6.53) and 1.72 (1.04–2.84) respectively) were correlated with androgen level of PCOS patients.

Conclusion

Our study showed that FKBP5 gene polymorphisms are associated with PCOS generally (rs1360780 and rs3800373) and with the hyperandrogenism subtype specifically (rs1360780, rs9470080, rs9296158, rs1043805 and rs7757037).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01301-0.

The role of aquaporins in polycystic ovary syndrome - A way towards a novel drug target in PCOS

Aquaporins (AQPs) are transmembrane proteins, able to transport water (and in some cases also small solutes, e. g. glycerol) through the cell membrane. There are twelve types of aquaporins (AQP1-AQP12) expressed in mammalian reproductive systems. According to literature, many diseases of the reproductive organs are correlated with changes of AQPs expression and their malfunction. That is the case in the polycystic ovary syndrome (PCOS), where dysfunctions of AQPs 7-9 and alterations in its levels occur. In this work, we postulate how AQPs are involved in PCOS-related disorders, in order to emphasize their potential therapeutic meaning as a drug target. Our research allows for a surprising inference, that genetic mutation causing malfunction and/or decreased expression of aquaporins, may be incorporated in the popular insulin-dependent hypothesis of PCOS pathogenesis. What is more, changes in AQP's expression may affect the folliculogenesis and follicular atresia in PCOS.

Association of single-nucleotide polymorphisms rs2197076 and rs2241883 of FABP1 gene with polycystic ovary syndrome

PURPOSE

The objective of this study was to evaluate the association between single-nucleotide polymorphisms (SNPs) rs2197076 and rs2241883 in fatty acid-binding protein 1 (FABP1) gene and polycystic ovary syndrome (PCOS).

METHODS

The two alleles rs2197076 and rs2241883 in FABP1 gene in 221 PCOS women and 198 normal women were amplified and sequenced. Allele frequency comparison was performed between the PCOS and control groups, and genotype-phenotype correlation analysis was performed using dominant and recessive models to assess the association of FABP1 and the main features of PCOS.

RESULTS

Allele frequency analyses showed a strong association of SNPs rs2197076 and rs2241883 of FABP1 gene with PCOS (P < 0.001). The additive, dominant, and recessive genotype model analyses further supported this association even after adjusting for age and body mass index (BMI). The minor allele frequency (MAF) of rs2241883 in obese PCOS women was less than that in obese control women. Further genotype-phenotype correlation analysis showed that SNP rs2197076 had a stronger association with the main features of PCOS than SNP rs2241883.

CONCLUSION

In the association of SNPs in FABP1 gene with PCOS, rs2197076 was more closely associated with its main features than rs2241883 and seemed to play a more important role in the pathogenesis of PCOS.

Association Study between Polycystic Ovarian Syndrome and the Susceptibility Genes Polymorphisms in Hui Chinese Women

Introduction

Polycystic ovary syndrome (PCOS) is one of the most common endocrine-metabolic disorders. Evidence of familial aggregation analysis and different clinical traits among different regions and ethnicities indicated that the pathogenesis of PCOS is associated with multiple genetic and environmental factors. Our previous research had identified three susceptibility loci (rs2479106, DENND1A; rs13405728, LHCGR; rs13429458, THADA) for PCOS in Han Chinese women. The overall aim of this study was to investigate the relationship between three susceptibility gene polymorphisms and PCOS in Hui ethnic women.

Methods

151 patients with PCOS (case group) and 99 healthy women (control group) were recruited from the Reproductive Medicine Center of the General Hospital of Ningxia Medical University. Clinical data and serum hormone characteristics of case and control groups were collected and analyzed. The three susceptibility single-nucleotide polymorphisms have been replicated in both case and control groups. Gene polymorphisms were detected by direct sequencing after polymerase chain reaction.

Results

The Body Mass Index, LH, LH/FSH ratio and total testosterone were significantly elevated in PCOS patients compared to control group (P<0.05). The frequencies of genotype and allele in rs13405728 were significantly different between the PCOS and the control groups (P<0.05). Of the SNP rs13405728, the PCOS cases with TT genotype stayed at a higher level of total testosterone, TG and LDL than those with the CC and CT genotypes. In contrary, there was no statistical difference between the two groups for SNP rs13429458 and rs2479106 (P>0.05).

Conclusion

The present study suggested that the SNP rs13405728 in the LHCGR gene was associated with PCOS in Hui ethnic women, and its TT genotype characterized with higher level of TT, TG and LDL.

Anti-mullerian hormone as a diagnostic and prognostic tool for PCOS patients

Purpose

To determine whether the measurement of serum AMH can be used to diagnose PCOS and as a tool to predict the prognosis of PCOS.

Methods

This is a case–control study. Women of reproductive age (18–35 years) were recruited consecutively at a tertiary academic hospital during the period of March 2009–October 2011 and were divided into case (PCOS patients defined by the Rotterdam criteria) and control groups (non-PCOS patients). Menstrual history, clinical manifestations of hyperandrogenism, ovarian ultrasound assessments, and the levels of AMH, LH, FSH, and estradiol were collected.

Results

Seventy-one cases and 71 controls were recruited. AMH serum levels were significantly higher in PCOS patients than in controls. The Area Under the Curve (AUC) of the serum AMH assay in PCOS patients reached a value of 0.870. With a cut-off value of 4.45 ng/ml, the serum AMH level had a sensitivity of 76.1 % and a specificity of 74.6 %. The most common phenotypes of PCOS in this study were anovulation and polycystic ovary (63.4 %). However, the mean level of AMH was highest in the phenotypes of anovulation, polycystic ovaries and hyperandrogenism (11.1 ng/ml).

Conclusions

In Indonesian women, AMH can be used as an alternative diagnostic criteria for PCOS patients with a cut-off value of 4.45 ng/ml. AMH value rise when hyperandrogenism is present therefore serum AMH levels also reflect the phenotype of PCOS. However, these findings must be confirmed with larger clinical studies.

Polycystic ovary syndrome in the pediatric population

Polycystic ovary syndrome (PCOS) is a common disorder characterized by hyperandrogenism and disordered gonadotropin secretion, often associated with insulin resistance. The syndrome, which modulates both hormonal and metabolic processes, is the most common endocrinopathy in reproductive-age women and increases a woman's risk of infertility, endometrial pathology, and cardiometabolic disease. As it is currently defined, PCOS most likely encompasses several distinct diseases with similar clinical phenotypes but different underlying pathophysiological processes. However, hyperandrogenism remains the syndrome's clinical hallmark. The clinical manifestations of PCOS often emerge during childhood or in the peripubertal years, suggesting that the syndrome is influenced by fetal programming and/or early postnatal events. However, given that the full clinical spectrum of PCOS does not typically appear until puberty, a "two-hit" hypothesis has been proposed: (1) a girl develops hyperandrogenism via one or more of many different potential mechanisms; (2) the preexisting hyperandrogenism subsequently disturbs the hypothalamic–pituitary–ovarian axis, resulting in ovulatory dysfunction and sustained hyperandrogenism. No consensus guidelines exist regarding the diagnosis and management of PCOS in the pediatric population; however, because the syndrome is a diagnosis of exclusion, the clinical evaluation of girls suspected of having PCOS is aimed at excluding other causes of androgen excess and menstrual dysfunction. For the syndrome's management, emphasis is placed on lifestyle and symptom-directed treatment.

Umbilical vein testosterone in female infants born to mothers with polycystic ovary syndrome is elevated to male levels

The aetiology of polycystic ovary syndrome (PCOS) is poorly understood, but an intrauterine hyperandrogenic environment has been implicated. This study was designed to assess whether the female offspring of mothers with PCOS are exposed to raised levels of testosterone (T) in utero. In this case-control study, three groups of pregnant women were recruited from the labour ward: PCOS women with a female baby (n = 10, PCOS girls); control women with a female baby (n = 20, control girls) and control women with a male baby (n = 10, control boys). Maternal and umbilical vein (UV) blood was assayed for T levels. UV T in PCOS girls was significantly raised, compared with control girls (p < 0.012). The difference in UV T between PCOS girls and control boys was not significant (p < 0.254). This is the first demonstration of a hyperandrogenic in utero environment in PCOS pregnancies; UV T in female infants is raised to male levels.

Adiponectin and polycystic ovary syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) has a prevalence of 5-8% in women of reproductive age. Women with PCOS have an increased risk of metabolic syndrome and associated comorbidities. Adiponectin is a circulating protein produced by adipocytes. Circulating levels of adiponectin are inversely related to adipocyte mass. Low levels occur with insulin resistance, type 2 diabetes, metabolic syndrome, and obesity-related cardiovascular disease. This article reviews the literature on the link between adiponectin and PCOS and the potential use of adiponectin as a biomarker for PCOS.

METHOD

Data-based studies on adiponectin and PCOS and adiponectin measurement were identified through the Medline (1950-2009) and ISI Web of Knowledge (1973-2009) databases.

RESULTS

Fifteen studies related to adiponectin and PCOS met inclusion criteria and were included in this review. These studies present evidence that adiponectin is linked to insulin resistance, insulin sensitivity, body mass index (BMI), and adiposity. In women with PCOS, lower levels, as opposed to higher levels, of adiponectin occur in the absence of adiposity.

CONCLUSION

The relationships between adiponectin and insulin resistance and sensitivity, metabolic syndrome, and BMI in women with PCOS suggest that adiponectin potentially could serve as a marker for disease risk and provide opportunity for earlier intervention if knowledge is successfully translated from laboratory to clinical practice. However, further study of the relationship between adiponectin and PCOS is required before there can be direct application to clinical practice.

Androgens and polycystic ovary syndrome

PURPOSE OF REVIEW

Polycystic ovary syndrome (PCOS) is a common complex endocrine genetic disorder, which involves overproduction of androgens, leading to heterogeneous range of symptoms and associated with increased metabolic and cardiovascular morbidity. This review focuses on androgen biosynthesis, use, metabolism in PCOS and clinical consequences of hyperandrogenism.

RECENT FINDINGS

Controversial definition of the disorder and different phenotypic subgroups present a challenge for clinical and basic research. Further investigation of different phenotypes highlights the fact that PCOS probably represents a group of disorders with different etiologies. Prenatal androgen exposure and adolescent studies suggest early in life androgen excess as initiating factor of PCOS, but insufficient evidence available to confirm this hypothesis. Various intracellular signaling pathways implicated in PCOS steroidogenesis and in androgen action have been studied, however, PCOS pathogenesis remains obscure. Growing evidence links androgens with pathophysiology of PCOS and metabolic derangements.

SUMMARY

Despite intensive investigation, etiology and underlying mechanisms of PCOS remain unclear, warranting further investigation. Better understanding of molecular and genetic basis might lead to invention of novel therapeutic approaches. Long-term interventional studies that lower androgen levels in women with hyperandrogenism might protect against metabolic and cardiovascular comorbidities are needed.

The biology of infertility: research advances and clinical challenges

Reproduction is required for the survival of all mammalian species, and thousands of essential 'sex' genes are conserved through evolution. Basic research helps to define these genes and the mechanisms responsible for the development, function and regulation of the male and female reproductive systems. However, many infertile couples continue to be labeled with the diagnosis of idiopathic infertility or given descriptive diagnoses that do not provide a cause for their defect. For other individuals with a known etiology, effective cures are lacking, although their infertility is often bypassed with assisted reproductive technologies (ART), some accompanied by safety or ethical concerns. Certainly, progress in the field of reproduction has been realized in the twenty-first century with advances in the understanding of the regulation of fertility, with the production of over 400 mutant mouse models with a reproductive phenotype and with the promise of regenerative gonadal stem cells. Indeed, the past six years have witnessed a virtual explosion in the identification of gene mutations or polymorphisms that cause or are linked to human infertility. Translation of these findings to the clinic remains slow, however, as do new methods to diagnose and treat infertile couples. Additionally, new approaches to contraception remain elusive. Nevertheless, the basic and clinical advances in the understanding of the molecular controls of reproduction are impressive and will ultimately improve patient care.

Polycystic ovary syndrome in adolescents

BACKGROUND

Polycystic ovary syndrome (PCOS) is the commonest endocrine disorder in women and typically presents during adolescence. The clinical and biochemical presentation is heterogeneous, but elevated serum concentrations of androgens are the most consistent biochemical abnormality and may be considered to be the hallmark of the syndrome. Many women with PCOS also have insulin resistance and hyperinsulinaemia, which may contribute to the clinical and endocrine abnormalities. The aetiology of PCOS is not clear but studies in the Rhesus monkey suggest that exposure to excess androgen during intrauterine life results in many of the features of human PCOS, including ovarian dysfunction, abnormal LH secretion and insulin resistance.

OBJECTIVE

To review the studies from the literature, including those of the author, regarding aetiology, presentation and management of PCOS in adolescents.

RESULTS AND CONCLUSIONS

We have proposed that PCOS in adolescents arises as a result of a genetically determined disorder of ovarian function that results in hyper-secretion of androgens, possibly during fetal life and also during physiological activation of the hypothalamic-pituitary-ovarian in infancy and at the onset of puberty. There is plentiful evidence for a genetic basis for PCOS (it appears to be a complex endocrine disorder resulting from the effects of a several genes), but environmental factors, notably nutrition, influence the clinical and biochemical phenotype. Obesity unmasks or amplifies symptoms, endocrine and metabolic abnormalities. The increasing incidence of childhood obesity has resulted in an alarming Increase not only in distressing symptoms but also impaired glucose tolerance and even diabetes among adolescent girls with PCOS. The search for PCOS genes in this condition, that is not only heterogeneous but also presents only in women of reproductive age, is not straightforward and has produced few convincing candidates so far. In due course, however, identification of the major susceptibility loci is likely to provide key insight into the aetiology of the syndrome and improve diagnosis and management.

Small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA), a candidate gene for polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a heterogenic, complex common genetic disease. Multiple pathways are involved in its pathogenesis, including the androgen signaling pathway and insulin signaling pathway. Small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) is a putative member of the androgen receptor-chaperone-co-chaperone complex, and may play a role in androgen signaling as a co-chaperone. Polymorphisms in the SGTA gene have not been evaluated for a role in PCOS.

METHODS

Women with and without PCOS (287 cases, 187 controls) were genotyped for three single nucleotide polymorphisms (SNPs) in SGTA. SNPs and haplotypes were determined and tested for association with PCOS and component traits of PCOS.

RESULTS

For SNP rs1640262, homozygotes for the minor allele were protected against PCOS (P = 0.009). Haplotype 1 (G-A-T) was associated with increased risk of PCOS (P = 0.015). In women with PCOS, haplotype 2 (A-G-C) was associated with increased insulin resistance (P = 0.013), consequently resulting in increased insulin secretion (P = 0.014).

CONCLUSIONS

This study presents genetic evidence suggesting a potential role of SGTA in the pathogenesis of PCOS. SGTA may provide a connection between multiple pathways in PCOS.

Nonreplication of the type 5 17beta-hydroxysteroid dehydrogenase gene association with polycystic ovary syndrome

CONTEXT

Increased androgen production is a primary feature of polycystic ovary syndrome (PCOS) and appears to be an inherited trait. The gene for the steroidogenic enzyme type 5 17beta hydroxysteroid dehydrogenase (HSD17B5) was implicated as a candidate for the hyperandrogenemia of PCOS by a previous study that demonstrated an association of a single nucleotide polymorphism (SNP) in the promoter of this gene with PCOS.

OBJECTIVE

The objective of the study was to replicate the previous report of association between the HSD17B5 gene and PCOS risk by genotyping the promoter SNP (as well as other SNPs in the region to provide improved coverage of the gene) in a large, well-characterized cohort suitable for replication study.

DESIGN

Women with and without PCOS were genotyped for five SNPs in HSD17B5. SNPs and haplotypes were determined and tested for association with PCOS risk and phenotypic markers of PCOS.

SETTING

Subjects were recruited from the reproductive endocrinology clinic at the University of Alabama at Birmingham; controls were recruited from the surrounding community. Genotyping took place at Cedars-Sinai Medical Center in Los Angeles.

PARTICIPANTS

Participants included 287 white women with PCOS and 187 white controls.

MAIN MEASUREMENTS

HSD17B5 genotype, PCOS risk, and testosterone levels were measured.

RESULTS

No SNP or haplotype was significantly associated with PCOS risk, testosterone, or any of the traits tested.

CONCLUSIONS

These data suggest that polymorphisms in the HSD17B5 gene are not associated with PCOS risk or elevated testosterone as previously reported.