What common genes link Polycystic Ovary Syndrome and type 2 diabetes according to recent studies?
Polycystic ovary syndrome (PCOS) and type 2 diabetes (T2D) often occur together, and research suggests they share common genetic roots. Recent studies have identified specific genes and epigenetic changes that may link the two conditions. The insulin gene VNTR (variable number of tandem repeats) is one key genetic variant linked to both PCOS and T2D risk. Additionally, epigenetic modifications—changes in how genes are expressed—in genes involved in insulin signaling and metabolism have been found in women with PCOS, which may also increase T2D susceptibility.
What the research says
A landmark 1997 study found that the INS VNTR III/III genotype was strongly associated with PCOS, with odds ratios of 8.20 and 5.70 in two independent groups 11. This same VNTR region regulates insulin expression, and the III/III genotype is also linked to higher insulin levels and T2D risk, suggesting a shared genetic susceptibility 11. More recent research has focused on epigenetic changes. A 2024 review reported that women with PCOS have global DNA hypomethylation and specific methylation changes in genes involved in hormone and metabolic pathways, many of which are also implicated in T2D 9. A 2025 systematic review identified 111 genes with altered DNA methylation in PCOS, including genes related to insulin signaling and glucose metabolism, which are central to T2D 10. These epigenetic modifications may explain how environmental factors influence both PCOS and T2D risk 910. While the provided sources do not directly study T2D genetics in PCOS populations, the overlap in affected pathways—such as insulin regulation and metabolic signaling—strongly suggests common genetic and epigenetic links.
What to ask your doctor
- Could my family history of type 2 diabetes affect my PCOS risk or treatment?
- Are there any genetic tests available that might help understand my risk for both PCOS and diabetes?
- How do insulin resistance and genetics influence my PCOS symptoms and long-term health?
- Should I be screened for type 2 diabetes more often because of my PCOS diagnosis?
- What lifestyle or medication options can help manage both PCOS and diabetes risk together?
This question is drawn from common patient questions about OB/GYN & Women's Health and answered using cited medical research. We do not provide individualized advice.