Brain Scans Show Similarities in Children with Autism and Their Siblings

According to a recent study performed by researchers at the University of Cambridge, children with autism and their siblings share similar patterns of reduced activity in brain regions linked to empathy.

The researchers anticipate that the results of this study may lead to a better understanding of the role genes play in autism, as well as the development of more methods which could be useful in foretelling a child’s risk for autism.

The study was conducted by a team of researchers led by Dr. Michael Spencer. The researchers studied the brains of autistic children and their family members by using functional Magnetic Resonance Imaging (fMRI) in order to detect active areas of the brain in response to images of different human expressions.

Spencer and his colleagues began by comparing the brains of autistic children to children with no family history of autism. They discovered that children with autism exhibited decreased brain activity in regions involved in responding to the emotions of others. While this finding is not new, the researchers went further and focused on unaffected siblings of their autistic participants.

By looking at the un-autistic siblings, the researchers discovered an analogous pattern of reduced activity in the same brain regions that were affected in the autistic children.

Spencer reported that, “We were struck by how similar the activity was in unaffected brothers and sisters compared to their sibling with autism. [This] seems to suggest that this is a shared pattern of activity due to inherited genes that may make family members at increased risk of autism.”

Prior studies have shown that a genetic basis for autism, as children with an older sibling with autism are twenty times more likely to be autistic than the general population. It is still not clear why this occurs, however, and further, it is not known which genes are connected to the increased risk of developing autism.

This study is the first to connect an individual’s ability to identify facial emotion in siblings with and without autism.

Spencer continued to state that, “The brain's response to facial emotion could be a fundamental building block in causing autism and its associated difficulties. It is likely that in the sibling who develops autism, additional, as yet unknown steps — such as further genetic, brain structure or function differences – take place to cause autism.”

The authors of this study anticipate this research to lead to improved screening or even treatment for autism in the future, but they also believe that these results are just the beginning of a long line of research focusing on the many factors which impact the development of autism.

This study was published in the journal Translational Psychiatry.