Increased risk of autism appears to be linked to the Y chromosome, according to a new study.
- Increased risk of autism appears to be linked to the Y chromosome, according to a new study.
- Autism is estimated to be 4 times more common in men compared to women.
- Further work is needed to understand the mechanisms at play in this association.
Around 700,000 people are affected by autism spectrum disorders (ASD) in France. The figures also show a higher prevalence of autism among males (four boys for every girl).
A team from the Geisinger health organization made a discovery that could explain this phenomenon: the increased risk is linked to the Y chromosome.
Their work was presented in the journal Nature CommunicationsOctober 15, 2024.
Autism: a risk factor associated with the Y chromosome
To try to understand the predominantly male prevalence of autism, researchers wanted to precisely determine the effects of the X and Y chromosomes on the risk of autism. They thus studied the genetic data of 177,416 people who participated in the Simons Foundation Powering Autism Research study. Among other things, they identified people who had an abnormal number of sex chromosomes and compared them to the diagnosis of autism.
They found that people with an extra X chromosome had no change in risk of autism spectrum disorder. In contrast, volunteers who had an extra Y chromosome were twice as likely to be diagnosed with autism.
For experts, these results suggest the existence of a risk factor associated with the Y chromosome rather than a protective effect of the X chromosome, as many scientists had suggested.
Autism and the sex chromosome: further research needed
“While these may seem like two sides of the same coin, our results encourage us to look for risk factors for autism on the Y chromosome instead of limiting our search to protective factors on the X chromosome.”explains Dr. Alexander Berry, co-director of the study, in a press release.
This work also confirms previous studies which had determined that the loss of a sex chromosome (known as Turner syndrome) is associated with a sharp increase in the risk of autism spectrum disorders.
The authors wish to organize further research to more precisely identify the specific risk factor associated with the Y chromosome and its mechanism.