Autism spectrum disorder (ATS) is more common in boys than in girls (2-5 times). Some evidence suggests that this increased prevalence in males might be due to the biological male phenotype. This research aims to derive correlations between the increased risk of ASD and normative sex-related phenotypic diversity in brain structure.

This is a cross-sectional, multivariate probabilistic classification study that includes 98 right-handed, high-functioning adults with diagnosed ASD, along with 98 matched control individuals aged 18-42 years. The researchers developed a predictive model of biological sex based on cortical thickness levels. The primary outcome of the study was the estimation of ASD probability as a function of normative sex-related diversity in brain structure.

Out of 98 participants with ASD, 49 were male and 49 female, with a mean age of 26.88 years. The researchers found that the sample probability of ASD did not increase with predictive probabilities for the male neuroanatomical brain phenotype. The findings also indicated that the patterns of sex-related neuroanatomical variability linked to ASD probability were sex-specific.

The research concluded that the male normative sex-related phenotypic diversity in brain structure is not associated with an increased intrinsic risk of autism spectrum disorder than the female neurophenotype.