Early Detection of Autism

Autism spectrum disorder (ASD) is a developmental disorder that affects communication and behavior. About one in 68 children born in the United States are diagnosed with ASD, but doctors cannot definitively diagnose autism until children start talking and interacting with others, which occurs around the age of 2. Neuroscientists are trying to investigate brain differences with infants at an increased risk of ASD and infants with low-risk with the hope to prove a way for early detection of autism.  

In her article, “Doctors Are Getting Closer to Predicting Autism Earlier”, Alice Park describes a study by Heather Cody Hazlett of Carolina Institute of Developmental Disabilities at the University of North Carolina. Hazlett took MRI scans of 6 month olds, 12 month olds and 24 month olds to track changes of those children’s brain up to the age of 2. By doing a longitudinal study, Hazlett was able to match the infant brain scans with the autism diagnosed scans, if the child happened to be diagnosed with autism. She found that the brains looked very different from those who did not develop autism. The brain scans with autism showed an increase in size of the nerve cells in the cortex between the age of 6 months to 12 months. She describes that with more brain surface, the brain grew faster the first year of life. As the first symptoms of autism emerged around the age of 2 years old, their brains already experienced different patterns of brain development compared to the children who were not diagnosed. Hazlett overall developed a formula predicting which infants were likely to develop ASD. Park believes this could be the foundation to a new understanding of which infants are likely to be diagnosed of this developmental disorder at an early. 

Recent studies have examined electrophysiological responses to faces in infants with increased-risk of ASD as a means to understand “early developmental sequences of risk”. Maggie Guy in, “Neural correlates of face processing in etiologically-distinct 12-month-old infants at high-risk of autism spectrum disorder”, examines neural correlates of faces and object processing in 12-month old infants with increased risk of ASD, infants with FXS (Fragile-X Syndrome) and low-risk controls. She believed “examining the early emergence of ASD-associated features in FXS may inform early risk factors specific to FXS, as well as broader heterogeneous pathways of ASD emergence”. The shared behavioral ASD features among these three groups, may ultimately have roots in distinct neural mechanisms showing specific brain development patterns which may contribute to atypicalities in social behavior. “Investigating early patterns of face processing among infants with high-risk of ASD can inform both early markers of ASD risk, as well as broader endophenotypes of ASD that manifest in clinically unaffected individuals”.

If a foundation of similar electrophysiological responses for children with high-risk of ASD is discovered, who are later diagnosed with autism, this could possibly create a baseline for early detection of autism. To do this, more studies, similar to Hazlett’s, would have to perform longitudinal studies to compare the infant brain scans with the autism-diagnosed 2-year-old brain scan. If early detection of ASD were capable before the age of two years old, some learning programs may possibly be able to minimize some of the learning and communication symptoms of autism. These learning processes would only be useful if they began early in the infant’s life which is why discovering possible ways to detect autism early is imperative. 

References:

Guy, Maggie W., et al. “Neural Correlates of Face Processing in Etiologically-Distinct 12-Month-Old Infants at High-Risk of Autism Spectrum Disorder.” Developmental Cognitive Neuroscience, vol. 29, 2018, pp. 61–71., doi:10.1016/j.dcn.2017.03.002.

Park, Alice. “Doctors Are Getting Closer to Predicting Autism Earlier.” Time, 15 Feb. 2017, time.com/4672316/autism-spectrum-disorder-babies-2/.