(RxWiki News) Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have long mystified scientists. It turns out these conditions may actually overlap.
New research has uncovered new genes associated with ADHD - genes that are also found in autism and other brain abnormalities - what scientists call neuropsychiatric conditions.
"ADHD and autism share some of the same genes."
The research, conducted at the University of Toronto, used gene-chip technology to examine the DNA of 248 unrelated people with ADHD.
Researchers were looking specifically for variations in the genes called copy number variants or CNVs. They found some CNVs that were new to the child and some that had been inherited.
Among the inherited genes, researchers found some that are also seen in ASD.
To explore this overlap, they tested a different group of 349 children who had been diagnosed with austism. Nine of these children had genes related to ADHD.
Lead investigator, Dr. Russell Schachar, senior scientist and psychiatrist at The Hospital for Sick Children and professor of psychiatry at the University of Toronto, says the study has identified for the first time what he calls "decent ADHD candidate genes."
Schachar goes on to say people with the same CNVs can have very different symptoms.
Most people with ADHD have other conditions, such as anxiety or problems with mood, behavior or language. Similarly, about three-quarters of individuals with ASD also have either attention disorders or hyperactivity.
So these co-existing conditions are probably linked because of shared genetic risks, according to Schachar.
This research could change how scientists look at neuropsychiatric conditions. Rather than exploring only one, now researchers can look across disorders, Schachar says.
More research is needed to determine why common risks develop into different disorders.
This study is published in Science Translational Medicine.