The Genetic Underpinnings of Gender Differences in Autism Spectrum Disorder
Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder with a male-to-female prevalence ratio of 4:1. The genetic mechanisms that underlie this gender difference, however, remain somewhat elusive.
Recent research has shed some light on this topic, suggesting that females may require a higher 'genetic load' to reach the threshold for an ASD diagnosis. This is evidenced by the fact that the prevalence of putative functional de novo mutations (loss-of-function and predicted deleterious missense mutations) in females is significantly higher than that in males.
Moreover, ASD candidate genes are found to be more frequently co-expressed in female brains than in male brains. This suggests that compensation effects of the deficiency of ASD candidate genes may be more likely in females.
However, it's important to note that male and female-specific genes are co-expressed with each other, suggesting a convergent functional network of male and female-specific genes.
This research provides suggestive evidence supporting the 'female-protective effect' in ASD, a theory that posits that females have a higher threshold for ASD due to protective genetic factors.
Further research is needed to fully understand the genetic mechanisms that contribute to the gender differences in ASD prevalence. Integrating neuronal and hormonal data may provide more insights into the underlying gender difference in ASD.
