The Brain Phenotype in Polycystic Ovary Syndrome (PCOS): Androgens, Anovulation, and Gender

Polycystic ovary syndrome (PCOS) is a common condition with reproductive and metabolic features. Recent studies confirmed that women with PCOS have multiple genetic allelic variants that are independently associated with hyperandrogenism, gonadotropin regulation, timing of menopause, depression, and metabolic disturbances, including insulin resistance [1]. Of note, the data cited above showed that not all women with PCOS possess the full complement of the 14 genetic variants identified. Genetic heterogeneity results in clinical heterogeneity. We have long recognized that there is a spectrum of clinical presentation, with some women having a more pronounced reproductive phenotype and others presenting primarily with metabolic features. Despite variation related to PCOS genotype and phenotype, however, two long-recognized pathogenic themes remain the same: excess androgen exposure and insulin resistance. Since androgens and insulin modulate of brain architecture and function, it is not surprising that PCOS is associated with a brain phenotype, but also one that presents variably. Building on the notion that the brain is a target of hormones of all classes, in this chapter we characterize the brain phenotype in PCOS and explore the evidence that the brain phenotype is the result of androgen exposure that not only predisposes to anovulation and obesity but also has the potential to skew gender identity and sexual orientation.