Polycystic Ovary Syndrome (PCOS) is now established as a complex and multifactorial endocrine disorder that affects a significant number of women globally, with a prevalence ranging from 8-13% depending on the diagnostic criteria and population studied. Â
A study by Khan, Ullah, and Basit provides a comprehensive overview of the genetic and molecular understanding of PCOS. The study emphasizes that PCOS is a polygenic disorder with no single genetic marker fully explaining the condition. About 72% of risk variants identified highlighted their hereditary involvement and their interplay with one another along with other extrinsic factors, contribute to the development and manifestation of PCOS.
The study also highlighted several genes involved in ovarian and adrenal steroidogenesis, including CYP11a, CYP17, and CYP19, which are crucial for androgen production and metabolism. Mutations and polymorphisms in these genes may lead to elevated androgen levels, a hallmark of PCOS. Additionally, genes involved in insulin signaling, such as INSR and IRS-1, also play a significant role, as insulin resistance is a common feature in many women with PCOS.
Genome-wide association studies have further revealed associations between PCOS and other conditions such as obesity, type 2 diabetes, and heart disease, indicating shared genetic factors in their development. Researchers identified 14 specific genetic loci associated with PCOS through a large-scale analysis involving over 10,000 PCOS cases and more than 100,000 controls of European ancestry. Among these loci, three genetic variations (PLGRKT with SNP-rs10739076, ZBTB16 with SNP-rs1784692, and MAPRE1 with SNP- rs853854) were newly discovered along with others (THADA, GATA4/NEIL2, YAP1, etc.) that have been previously observed in Han Chinese and European populations. Although obesity is commonly associated with PCOS, the study did not reveal new loci, most genetic variants showed consistent effects across PCOS symptoms such as hormone imbalances and ovarian issues.Â
Another study highlights the challenges of identifying risk variants through GWAS, as most of these variants are non-coding (parts that do not directly encode proteins) and located in regulatory regions of the genome. However, about 60% of these variants are found in DNA hypersensitivity and regulatory regions. For example, variants near the FSHβ gene (SNPs- rs11031006 and rs11031005) not only increase the risk for PCOS but are also associated with lower follicle-stimulating hormone (FSH) and higher luteinizing hormone (LH) levels. These instances show how non-coding variants may influence gene expression and hormone levels, contributing to the risk of PCOS. Researchers have also used Mendelian randomization to demonstrate that genetic influences for traits such as BMI, fasting insulin, and age at menopause are more frequent in women with PCOS, suggesting these traits causally contribute to the syndrome.Â
Understanding the genetic factors behind Polycystic Ovary Syndrome (PCOS) offers valuable insights into its impact on women’s overall health- including reproductive, metabolic, and mental health.Â