Autism heritability was found to be 87% for males and 75.7% for females, highlighting notable genetic differences between the sexes, according to a recent study.

Heritability estimates had a statistically significant difference of 11.3%, according to a new study in JAMA Psychiatry.

A study population of 1,047,649 children born in Sweden between January 1, 1985, and December 31, 1998, were followed by researchers until age 19. Of the children, 12,226 (1.17%) were diagnosed with autism spectrum disorder (ASD).

Researchers aimed to estimate the sex-specific heritability of ASD using a large, population-based cohort from Sweden. Researchers conducted a retrospective analysis of national health register data encompassing 538,283 males (51.38%) and 509,366 females (48.62%), including non-twin siblings and cousins, to assess the relative variance in ASD risk due to genetic and environmental factors. Analysis took place from August 2022 through November 2023.

The analysis did not support a significant contribution of shared environmental factors to ASD risk, noted investigators. Issues with model specification were identified, including the inability to distinguish between the impacts of common and rare genetic variations on sex differences in ASD risk, or to account for phenotypic differences such as comorbid conditions.

Full disclosures can be found in the published study.