WEDNESDAY, Aug. 10 (HealthDay News) -- Some of the genetic variants implicated in ADHD (attention-deficit/hyperactivity disorder) overlap with genes and nerve communication pathways that play a role in autism, a new study finds.
The research may help to explain why people with ADHD, autism and other neuropsychiatric disorders sometimes have symptoms in common, such as impulsivity and restlessness, researchers said.
Instead of finding one or more "ADHD" or "autism" genes, research is beginning to uncover neural pathways that influence the way a brain develops and works, said senior study author Dr. Russell Schachar, a senior scientist and child psychiatrist at the Hospital for Sick Children in Toronto.
"What we are beginning to understand is that genes don't code for disorders as they appear in the diagnostic manual. Genes code for proteins that are needed for brain structure and brain function," Schachar said. "Many of the genes we discovered involved in both ADHD and [autism spectrum disorders] affect the development of the nervous system."
The study appears in the Aug. 10 issue of Science Translational Medicine.
ADHD is marked by difficulty paying attention, hyperactivity and impulsiveness. While it's known that ADHD has a strong genetic component, researchers have had limited success identifying specific genes or neural pathways that can explain it, the study authors said.
In the study, researchers analyzed the DNA of 248 children with ADHD, along with many of their parents. They found that about 9.4 percent of kids with ADHD (or about one in 10) had identifiable abnormalities known as copy number variations, which are changes in the DNA that cause an abnormal number of copies of one or more genes.
This means that on certain chromosomes, bits of DNA were deleted or duplicated. The copy number variations were on genes expressed, or activ
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