The disproportionate amount of male autism diagnoses has long puzzled scientists. Now a new study on female resilience to genetic mutations may finally shed some definitive light on the matter.

Dr. Sebastien Jacquemont, a researcher at the University Hospital of Lausanne in Switzerland and lead author of the new study, told reporters that the results represent a significant step toward a more solid understanding of the developmental disorder that now affects about one in 88 children. "This is the first study that convincingly demonstrates a difference at the molecular level between boys and girls referred to the clinic for a developmental disability,” he said. "The study suggests that there is a different level of robustness in brain development, and females seem to have a clear advantage."

The study, which is published in the American Journal of Human Genetics, analyzed genetic samples from nearly 16,000 people with neurodevelopmental disorders. The data from this cohort was then compared to similar data from 800 families affected by autism spectrum disorders (ASDs).

The team found that females diagnosed with a neurodevelopmental disorder like autism had a greater number of harmful genetic aberrations compared to their male counterparts. According to Jacquemont, this suggests that the developing female body need more severe genetic mutations to approach the spectrum of neurodevelopmental disorder. "Overall, females function a lot better than males with a similar mutation affecting brain development," he explained.

Origins of Autism

With autism rates on the rise, the need for a robust theory of the disorder’s origin is becoming more and more urgent. Last year, researchers from Duke University showed that autism may be linked to induced or augmented labor. Similarly, McGill researchers have suggested that children born to mothers with lupus are twice as likely to develop the disorder.

Besides illuminating a possible reason behind the autism gender disparity, the new study offers an explanation to other male-dominated diagnoses like ADHD. According to Jacquemont, this could improve prevention strategies for a wide range of disorders. "Our findings may lead to the development of more sensitive, gender-specific approaches for the diagnostic screening of neurodevelopmental disorders," he said.

Source: Jacquemont S, Coe BP, Hersh M, Duyzend MH, et al. A Higher Mutational Burden in Females Supports a “Female Protective Model” In Neurodevelopmental disorders.