Scientists Explain Why Autism is More Common in Males
Experts have long known that the rate of neurodevelopmental disorders, such as autism, is higher in men than in women. But then, the underlying reasons remained unclear. Now, a new study published in the American Journal of Human Genetics provides an explanation for this observation.
In the study, researchers present compelling evidence that females require more extreme genetic mutations than do males to push them over the diagnostic threshold for neurodevelopmental disorders. A gender bias in the prevalence of neurodevelopmental disorders has been reported for ASD, intellectual disability, and attention deficit hyperactivity disorder.
Sébastien Jacquemont and his colleagues teamed up with Evan Eichler of the University of Washington School of Medicine to analyse DNA samples and sequencing data sets of one cohort consisting of nearly 16,000 individuals with neurodevelopmental disorders and another cohort consisting of about 800 families affected by ASD.
They analysed both copy-number variants (CNVs) — individual variations in the number of copies of a particular gene — and single-nucleotide variants (SNVs) — DNA sequence variations affecting a single nucleotide.
They found that females diagnosed with a neurodevelopmental disorder or ASD had a greater number of harmful CNVs than did males diagnosed with the same disorder.
Moreover, females diagnosed with ASD had a greater number of harmful SNVs than did males with ASD.
These findings suggest that the female brain requires more extreme genetic alterations than does the male brain to produce symptoms of ASD or neurodevelopmental disorders.
“Overall, females function a lot better than males with a similar mutation affecting brain development,” Jacquemont says.
“Our findings may lead to the development of more sensitive, gender-specific approaches for the diagnostic screening of neurodevelopmental disorders.” Jacquemont adds.
Source of this article:
Biological Explanation for Gender Disparity in Autism
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