On Oct. 17, 2024, Geisinger announced results of a study that showed increased risk for autism appears to be linked to the Y chromosome, offering a new explanation for the greater prevalence of autism in males.

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by impaired social interaction and communication, and restricted and repetitive patterns of behavior, interests and activities. ASD is nearly four times more prevalent among males than females, but the reason for this disparity is not well understood.

The team analyzed genetic and ASD diagnosis data on 177,416 patients enrolled in the Simons Foundation Powering Autism Research (SPARK) study and Geisinger’s MyCode Community Health Initiative. They found that individuals with an additional X chromosome had no change in ASD risk, but that those with an additional Y chromosome were twice as likely to have an ASD diagnosis. This suggests a risk factor associated with the Y chromosome instead of a protective factor associated with the X chromosome.

The study results were published in Nature Communications.