Genetics of sex differences in neuroanatomy and function

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Sex differences manifest across biological levels, including brain structure, function, behavior, and disease susceptibility.
• Historically, gonadal hormones were considered the primary drivers of these differences.
• Emerging evidence points to nonhormonal effects of sex chromosome genes as significant contributors.

Purpose of the Study:

• To review the four core genotype model, differentiating hormonal and sex chromosome influences on sex dimorphism.
• To highlight key genes, such as Sry, implicated in brain sex differences.
• To explore the genetic basis of neurochemistry, susceptibility to neurological/psychiatric disorders, and disorders of sexual development.

Main Methods:

• Review of existing literature on sex differences in biology and genetics.
• Analysis of the four core genotype model to disentangle genetic and hormonal effects.
• Focus on specific genes (e.g., Sry) and their roles in brain development and function.

Main Results:

• Sex chromosome genes, independent of hormones, directly influence brain dimorphism.
• Specific genes contribute to sex-specific neurochemistry and susceptibility to disorders.
• Sex-specific genetic factors play a role in disorders of sexual development.

Conclusions:

• Sex chromosome genetics represent a crucial, often overlooked, factor in biological sex differences.
• Further research into candidate genes is essential for understanding sex-biased disorders.
• Elucidating these mechanisms may enable the development of sex-specific therapeutic strategies.