A University of Virginia research team is tackling one of the most consistent and puzzling findings about autism spectrum disorder: Why are four times more boys diagnosed as having autism than girls?
“Is it that girls with autism express it differently and are therefore missed by diagnosis, or are there protective factors in their development that help them avoid developing autism?” said Kevin Pelphrey, a member of UVa’s Brain Institute with joint appointments in the School of Medicine and the Curry School of Education & Human Development.
Pelphrey, a neuroscientist, is in the midst of an ambitious project to meld data from brain scans of people with autism; gene sequencing; and long-term studies of boys and girls with autism as they move from childhood to adulthood.
He hopes the effort, which is supported by the National Institutes of Health’s Autism Centers of Excellence program, will illuminate biological determinants of autism, whether biological sex or self-perception of gender influence the development of autism, and how to use those findings to diagnose autism and predict outcomes in adolescence and young adulthood.
“One of our hypotheses is that the same behaviors in a boy and girl that give you a diagnosis of autism are caused by different differences in brains,” Pelphrey said. “It could be that the parts of the brain that correlate to autistic behavior are different, based on biological sex.”
Autism presents differently in every person. Children typically begin to show signs between ages 2 and 3, and early diagnosis and intervention can make a big difference in a child’s ability to interact with peers, communicate effectively and handle social situations.
However, the techniques used to diagnose the disorder are often based on stereotypically male behavior. A boy unusually obsessed with trains might quickly be assessed for autism, Pelphrey said, but a girl’s obsession with horses might be seen as normal, and remain overlooked. American girls, too, are often quicker to learn how to mask some symptoms of autism, according to previous studies.
The research is accompanied by many questions of perception and self-perception of identity. Researchers recently have found higher rates of autism among people who have gender dysphoria, or feel there is a mismatch between their gender and biological sex. Emerging research also indicates overlap between eating disorders and autism; people, especially girls, with anorexia often have trouble forming connections and regulating environments that predates the onset of an eating disorder.
Eventually, by looking at brain scans and genes, Pelphrey hopes to arrive at a biological test to diagnose autism and weed out misdiagnoses.
“What are biological markers of autism that we can use to monitor success of interventions?” he said. “And what can we use as a diagnostic indicator for autism, and will that marker be different for boys and girls?”
UVa committed $6.2 million to a cross-disciplinary project housed in the Curry School of Education & Human Development. It is known as Supporting Transformative Autism Research, or STAR, and supports a bevy of projects to improve screening tools, work on interventions for school-age children and adults, and specific life activities such as helping people with autism navigate meal times, dentist appointments and swimming.
Pelphrey has worked with Micah Mazurek, director of the STAR center, who has herself studied whether recent changes to the definition of autism might lead more girls to be missed by diagnostic tests.
“Kevin’s work is really important in terms of understanding differences at the neurological level between boys and girls, and will be helpful in terms of understanding how we make diagnostics better,” said Mazurek, who recently evaluated changes between diagnostic standards and discovered that the new standard is more likely to miss girls with autism.
The interplay between neuroscientists and clinicians is essential, Pelphrey said, because a better diagnosis can ensure that children quickly get interventions.
To learn more about research at UVa’s Brain Institute, visit: braininstitute.virginia.edu/autism.