Deconstructing a Syndrome: Genomic Insights into PCOS Causal Mechanisms and Classification

2022 ◽  
Author(s):  
Matthew Dapas ◽  
Andrea Dunaif

Abstract Polycystic ovary syndrome (PCOS) is among the most common disorders of reproductive-age women, affecting up to 15% worldwide, depending on the diagnostic criteria. PCOS is characterized by a constellation of interrelated reproductive abnormalities including disordered gonadotropin secretion, increased androgen production, chronic anovulation, and polycystic ovarian morphology. It is frequently associated with insulin resistance and obesity. These reproductive and metabolic derangements cause major morbidities across the lifespan, including anovulatory infertility and type 2 diabetes (T2D). Despite decades of investigative effort, the etiology of PCOS remains unknown. Familial clustering of PCOS cases has indicated a genetic contribution to PCOS. There are rare Mendelian forms of PCOS associated with extreme phenotypes, but PCOS typically follows a non-Mendelian pattern of inheritance consistent with a complex genetic architecture, analogous to T2D and obesity, that reflects the interaction of susceptibility genes and environmental factors. Genomic studies of PCOS have provided important insights into disease pathways and have indicated that current diagnostic criteria do not capture underlying differences in biology associated with different forms of PCOS. We provide a state-of-the-science review of genetic analyses of PCOS, including an overview of genomic methodologies aimed at a general audience of non-geneticists and clinicians. Applications in PCOS will be discussed, including strengths and limitations of each study. The contributions of environmental factors, including developmental origins, will be reviewed. Insights into the pathogenesis and genetic architecture of PCOS will be summarized. Future directions for PCOS genetic studies will be outlined.

2005 ◽  
Vol 26 (2) ◽  
pp. 251-282 ◽  
Author(s):  
Héctor F. Escobar-Morreale ◽  
Manuel Luque-Ramírez ◽  
José L. San Millán

The genetic mechanisms underlying functional hyperandrogenism and the polycystic ovary syndrome (PCOS) remain largely unknown. Given the large number of genetic variants found in association with these disorders, the emerging picture is that of a complex multigenic trait in which environmental influences play an important role in the expression of the hyperandrogenic phenotype. Among others, genomic variants in genes related to the regulation of androgen biosynthesis and function, insulin resistance, and the metabolic syndrome, and proinflammatory genotypes may be involved in the genetic predisposition to functional hyperandrogenism and PCOS. The elucidation of the molecular genetic basis of these disorders has been burdened by the heterogeneity in the diagnostic criteria used to define PCOS, the limited sample size of the studies conducted to date, and the lack of precision in the identification of ethnic and environmental factors that trigger the development of hyperandrogenic disorders. Progress in this area requires adequately sized multicenter collaborative studies after standardization of the diagnostic criteria used to classify hyperandrogenic patients, in whom modifying environmental factors such as ethnicity, diet, and lifestyle are identified with precision. In addition to classic molecular genetic techniques such as linkage analysis in the form of a whole-genome scan and large case-control studies, promising genomic and proteomic approaches will be paramount to our understanding of the pathogenesis of functional hyperandrogenism and PCOS, allowing a more precise prevention, diagnosis, and treatment of these prevalent disorders.


2019 ◽  
Author(s):  
Matthew Dapas ◽  
Frederick T. J. Lin ◽  
Girish N. Nadkarni ◽  
Ryan Sisk ◽  
Richard S. Legro ◽  
...  

AbstractBackgroundPolycystic ovary syndrome (PCOS) is a common, complex genetic disorder affecting up to 15% of reproductive age women worldwide, depending on the diagnostic criteria applied. These diagnostic criteria are based on expert opinion and have been the subject of considerable controversy. The phenotypic variation observed in PCOS is suggestive of an underlying genetic heterogeneity, but a recent meta-analysis of European ancestry PCOS cases found that the genetic architecture of PCOS defined by different diagnostic criteria was generally similar, suggesting that the criteria do not identify biologically distinct disease subtypes. We performed this study to test the hypothesis that there are biologically relevant subtypes of PCOS.Methods and FindingsUnsupervised hierarchical cluster analysis was performed on quantitative anthropometric, reproductive, and metabolic traits in a genotyped discovery cohort of 893 PCOS cases and an ungenotyped validation cohort of 263 PCOS cases. We identified two PCOS subtypes: a “reproductive” group (21-23%) characterized by higher luteinizing hormone (LH) and sex hormone binding globulin (SHBG) levels with relatively low body mass index (BMI) and insulin levels; and a “metabolic” group (37-39%), characterized by higher BMI, glucose, and insulin levels with lower SHBG and LH levels. We performed a GWAS on the genotyped cohort, limiting the cases to either the reproductive or metabolic subtypes. We identified alleles in four novel loci that were associated with the reproductive subtype at genome-wide significance (PRDM2/KAZN1, P=2.2×10-10; IQCA1, P=2.8×10-9; BMPR1B/UNC5C, P=9.7×10-9; CDH10, P=1.2×10-8) and one locus that was significantly associated with the metabolic subtype (KCNH7/FIGN, P=1.0×10-8). We have previously reported that rare variants in DENND1A, a gene regulating androgen biosynthesis, were associated with PCOS quantitative traits in a family-based whole genome sequencing analysis. We classified the reproductive and metabolic subtypes in this family-based PCOS cohort and found that the subtypes tended to cluster in families and that carriers of rare DENND1A variants were significantly more likely to have the reproductive subtype of PCOS. Limitations of our study were that only PCOS cases of European ancestry diagnosed by NIH criteria were included, the sample sizes for the subtype GWAS were small, and the GWAS findings were not replicated.ConclusionsIn conclusion, we have found stable reproductive and metabolic subtypes of PCOS. Further, these subtypes were associated with novel susceptibility loci. Our results suggest that these subtypes are biologically relevant since they have distinct genetic architectures. This study demonstrates how precise phenotypic delineation can be more powerful than increases in sample size for genetic association studies.


2014 ◽  
Vol 58 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Poli Mara Spritzer

Polycystic ovary syndrome (PCOS) is a common condition in women at reproductive age associated with reproductive and metabolic dysfunction. Proposed diagnosed criteria for PCOS include two out of three features: androgen excess, menstrual irregularity, and polycystic ovary appearance on ultrasound (PCO), after other causes of hyperandrogenism and dysovulation are excluded. Based on these diagnostic criteria, the most common phenotypes are the “classic PCOS” – hyperandrogenism and oligomenorrhea, with or without PCO; the “ovulatory phenotype” – hyperandrogenism and PCO in ovulatory women; and the “non-hyperandrogenic phenotype”, in which there is oligomenorrhea and PCO, without overt hyperandrogenism. The presence of obesity may exacerbate the metabolic and reproductive disorders associated with the syndrome. In addition, PCOS women present higher risk for type 2 diabetes and higher prevalence of cardiovascular risk factors that seems to be associated with the classic phenotype. The main interventions to minimize cardiovascular and metabolic risks in PCOS are lifestyle changes, pharmacological therapy, and bariatric surgery. Treatment with metformin has been shown to improve insulin sensitivity, lowering blood glucose and androgen levels. These effects are more potent when combined with lifestyle interventions. In conclusion, besides reproductive abnormalities, PCOS has been associated to metabolic comorbidities, most of them linked to obesity. Confounders, such as the lack of standard diagnostic criteria, heterogeneity of the clinical presentation, and presence of obesity, make management of PCOS difficult. Therefore, the approach to metabolic abnormalities should be tailored to the risks and treatment goals of each individual woman.


2021 ◽  
Vol 47 (3) ◽  
pp. 130-149
Author(s):  
Joanna Smyczyńska

Polycystic ovary syndrome (PCOS) is one of the most common hormonal disorders and causes of infertility in women in reproductive age. Diagnostic criteria of PCOS in adult women include: ovulation disorders, hyperandrogenism and  polycystic ovaries. According to most recommendations, 2 out of these 3 criteria are confirm the diagnosis of PCOS. In girls during puberty and in the first years after menarche, different diagnostic criteria of menstrual disorders should be taken into account (variable length of menstrual cycles, monophasic cycles) and the limited usefulness of ultrasound examination for PCOS diagnosis within 8 years after menarche. Fairly extensive differential diagnosis is also necessary, especially – exclusion of adrenal hyperandrogenism. Moreover, the diagnostic criteria of PCOS do not take into account the metabolic disorders found in most patients (obesity, insulin resistance, type 2 diabetes), which should be diagnosed as early as possible and treated appropriately. This is especially true for teenagers, in whom the unequivocal diagnosis of PCOS or its exclusion may be very difficult. Current recommendations regard hormonal contraception as the first-line therapy in PCOS, in both adult women and adolescents. Together with its beneficial effect on the reduction of hyperandrogenism and obtaining regular bleeding (which in fact are not menstruations), the unfavorable metabolic effects of hormonal contraception are emphasized, as well as the inadequacy of its use if it is expected to achieve or restore ovulation and fertility. The latest reports indicate the legitimacy of treatment aimed at correcting disorders of carbohydrate metabolism and its greater effectiveness compared to the use of oral contraceptives in both adult women and girls with PCOS. In the pharmacotherapy of insulin resistance, metformin is of fundamental importance, the use of pioglitazone, GLP-1 receptor agonists or inositols is also proposed. Adequate lifestyle and dietary modification are of major importance in the treatment and prevention of PCOS. The mechanisms of "inheritance" of PCOS and insulin resistance with the participation of epigenetic modifications are still better understood, taking into account the effects of exposure to androgen excess in utero, intrauterine growth retardation, and maternal obesity and hyperalimentation. This creates new possibilities for PCOS prophylaxis.


2020 ◽  
Vol 69 (4) ◽  
pp. 89-100
Author(s):  
Maria I. Yarmolinskaya ◽  
Elena I. Abashova ◽  
Olga L. Bulgakova

Polycystic ovary syndrome (PCOS) is a common endocrine pathology that affects 814% of women of reproductive age. The leading signs of the disease are hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. Over the past decades, a variety of animal models have been developed to study the etiology and pathogenesis of PCOS, including chemical, hormonal, and genetic interventions. However, a large number of experimental techniques differ even in the framework of a single model. In this review article, we summarized PCOS animal models using both direct hormonal effects and indirect methods.


2013 ◽  
Vol 154 (17) ◽  
pp. 650-657
Author(s):  
László Ságodi ◽  
Emőke Kiss-Tóth ◽  
László Barkai

Polycystic ovary syndrome is the most common heterogeneous endocrine abnormality in women in the reproductive age. The syndrome remains an enigmatic disorder because the aetiology is still unclear. Familial aggreagation is relatively common among patients with polycystic ovary syndrome suggesting a significant genetic component, although the way of inheritance has not been established firmly. The authors review the relevant medical literature and suggest that genetic and environmental factors play a role in the development of polycystic ovary syndrome. To date, no gene has been identified that causes or contributes substantially to the development of a polycystic ovary syndrome phenotype. Polycystic ovarian syndrome is considered to be an oligogenic disorder in which the interaction of a number of genetic and environmental factors determines the heterogeneous clinical and biochemical phenotype. To summarize current evidence the authors conclude, that when we are able to identify and then modify environmental determinants, then we will be able to safeguard better the health of those patients who are predisposed to disease development due to genotype or previous environmental effects. Orv. Hetil., 2013, 154, 650–657.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Deepika Garg ◽  
Reshef Tal

Polycystic ovary syndrome (PCOS) affects 5–10% of women in reproductive age and is characterized by oligo/amenorrhea, androgen excess, insulin resistance, and typical polycystic ovarian morphology. It is the most common cause of infertility secondary to ovulatory dysfunction. The underlying etiology is still unknown but is believed to be multifactorial. Insulin-sensitizing compounds such as inositol, a B-complex vitamin, and its stereoisomers (myo-inositol and D-chiro-inositol) have been studied as an effective treatment of PCOS. Administration of inositol in PCOS has been shown to improve not only the metabolic and hormonal parameters but also ovarian function and the response to assisted-reproductive technology (ART). Accumulating evidence suggests that it is also capable of improving folliculogenesis and embryo quality and increasing the mature oocyte yield following ovarian stimulation for ART in women with PCOS. In the current review, we collate the evidence and summarize our current knowledge on ovarian stimulation and ART outcomes following inositol treatment in women with PCOS undergoing in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI).


Sign in / Sign up

Export Citation Format

Share Document