Figure 1.

Hypothetical contribution of environmental, epigenetic, and genetic factors in the pathophysiology of PCOS. PCOS is a heterogeneous endocrine disorder and its pathogenesis is poorly understood. Current evidence supports gene-environment interactions and epigenetic regulation in the origins of PCOS. The inherited genetic component appears to span all organ systems and physiological function, with epigenetics capable of modifying the expression patterns of inherited genes. Environmental elements can influence all developmental components by impacting organ systems, physiological function and epigenetic regulation, with population-specific environmental elements thought to bring about ethnic differences in PCOS sub-phenotypes. While substantial gaps in knowledge still exist, further insights into our understanding of genetic and developmental contributions to the etiology of PCOS will significantly improve our ability to diagnose, treat, and prevent PCOS in the future.