Nearly five times as many boys as girls are diagnosed with autism. 1 out 54 boys has an autism spectrum disorder (ASD) while 1 out of 252 girls does, according to figures from the Centers for Disease Control and Prevention. Indeed, rare have been the times that, in the course of his years in special education, has my teenage autistic son, Charlie, had a female student in among his classmates.
A new study by American and European researchers addresses this “gender imbalance.” There might, says the study, be something about being female that has a “protective effect” in autism and actually stands in the way of more girls manifesting with autism as currently identified.
Is There a “Female Preventive Element” in Autism?
Under Elise Robinson, an instructor in analytic and translational genetics at Massachusetts General Hospital and Harvard Medical School, scientists looked at records from two large databases of fraternal twins that included information about autistic behaviors (difficulties in communication and social interactions, repetitive behaviors). Twins are especially of interest for such a study as they have the same genetic risk factors and are exposed to the same environmental hazards.
As Robinson and the other researchers found, among the girls, only those with a larger amount of familial risk factors showed signs of autistic behaviors (though not actually diagnosed with autism). To conclude this, the researchers examined siblings from two groups, boys and girls whose behaviors meant they would were in the top 10th percentile for having autistic behaviors. As the Boston Globe explains:
If gender had a protective effect, the researchers would expect girls to be more likely to have a sibling with autistic traits than boys in the same group. That’s because girls would need more familial risk factors to overcome the protective effect, and those same risk factors would also be experienced by their siblings.
The study does not only offer an explanation for why so many more boys than girls are diagnosed on the autism spectrum. John Gabrieli, a neuroscientist at the Massachusettts Institute of Technology, says in the Boston Globe that the study suggests that something biological, rather than environmental or genetic, could have a “muting” effect on girls manifesting traits of autism. Since this “preventive effect” is naturally occurring, understanding these biological mechanisms might actually provide “a suggestion of a treatment for boys or prevention for boys” or even some kind of preventive treatment that is “naturally-occurring.”
The very topic of preventing and curing autism is controversial, as more autistic individuals, both male and female, see being autistic as an intrinsic part of who they are; as part of their identity. The gender imbalance in autism has long been remarked upon by clinicians and others. Might it be that being a girl does not exactly “prevent” autism but lead to autism manifesting itself differently in girls and women and therefore going undetected — that is, does the new study instead provide reason for clinicians to revisit and even revise what is understood as autism?
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