Boys are three times more likely to be diagnosed with autism than girls, research suggests, and scientists found a link that may shine a light on why.
According to new research from the Geisinger College of Health Sciences in Pennsylvania, risk factors for autism may be linked to the Y chromosome.
Autism spectrum disorders are a diverse group of conditions characterized by some degree of difficulty with social interaction and communication, affecting roughly one in 100 children worldwide, according to data from the World Health Organization.
There are many potential causes of autism spectrum disorders, which include both environmental and genetic factors.
"A leading theory in the field is that protective factors of the X chromosome lower autism risk in females," Matthew Oetjens, an assistant professor at Geisinger's Autism & Developmental Medicine Institute, said in a statement.
However, Oetjens and his team at Geisinger College wanted to investigate whether the Y chromosome may also play a role.
To test this, the team analyzed a cohort of individuals with an abnormal number of X and Y chromosomes, a condition known as sex chromosome aneuploidy. These chromosomes, known as sex chromosomes, are the main factors in determining our sex, with XX usually resulting in females and XY usually resulting in males. However, roughly 1 in 450 newborns are born with more than two of these chromosomes, allowing the researchers to study their relative impacts on autism.
The study, published in the journal Nature Communications, explored the prevalence of autism spectrum disorders in 350 individuals with different variations of sex chromosome aneuploidy. What they found was that individuals with an extra X chromosome saw no change in their autism risk, whereas those with an additional Y chromosome were twice as likely to receive a diagnosis. This suggests that the risk factor may lie on the Y chromosome, rather than any protection coming from the X.
"While these may seem like two sides of the same coin, our results encourage us to look for autism risk factors on the Y chromosome instead of limiting our search to protective factors on the X chromosome," Alexander Berry, a staff scientist at Geisinger College and co-author on the study, said in a statement. "However, further research is needed to identify the specific risk factor associated with the Y chromosome."
Do you have a tip on a science story that Newsweek should be covering? Do you have a question about the U.S. population? Let us know via science@newsweek.com.
References
Berry, A. S. F., Finucane, B. M., Myers, S. M., Walsh, L. K., Seibert, J. M., Martin, C. L., Ledbetter, D. H., & Oetjens, M. T. (2024). A genome-first study of sex chromosome aneuploidies provides evidence of Y chromosome dosage effects on autism risk. Nature Communications, 15(1), 8897. https://doi.org/10.1038/s41467-024-53211-7
Loomes, R., Hull, L., & Mandy, W. P. L. (2017). What Is the Male-to-Female Ratio in Autism Spectrum Disorder? A Systematic Review and Meta-Analysis. Journal of the American Academy of Child and Adolescent Psychiatry, 56(6), 466–474. https://doi.org/10.1016/j.jaac.2017.03.013
English (US) ·