A new study published in Nature Genetics on December 4, 2011 has found variations in genes that involve the brain signaling pathways are linked to ADHD. This variation could help treat the disorder.
In the study, researchers conducted whole-genome analyses of 1,000 children with ADHD and 4,100 children without ADHD. Then evaluated the findings with other research involving nearly 12,000 subjects, 2,500 with ADHD and 9,200 without. The analyses found that at least 10 percent of children with ADHD also had “copy number variations” which means deletions or duplications of DNA sequences, in four of their genes that are part of the gene family glutamate receptor. The gene with the strongest result was GMR5. The study Dr’s explained that glutamate is a neurotransmitter, a protein that transmits signals between neurons in the brain.
In a written news release, Dr. Hakon Hakonarson, director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia said, “At least 10 percent of the ADHD patients in our sample have these particular genetic variants. The genes involved affect neurotransmitter systems in the brain that have been implicated in ADHD, and we now have a genetic explanation for this link.” He added, “Members of the GMR gene family, along with genes they interact with, affect nerve transmission, the formation of neurons, and interconnections in the brain, so the fact that children with ADHD are more likely to have alterations in these genes reinforces previous evidence that the GMR pathway is important in ADHD.”
Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children’s Medical Center of New York in New Hyde Park, N.Y. said, “This study is important not only in that it has identified gene variants that are associated with ADHD in approximately 10 percent of cases, but it identifies novel treatment strategies related to the neurotransmitter glutamate that researchers can now try to develop for individuals with the newly identified gene variants.” He added, “This study provides further evidence not only that ADHD has a genetic basis in a distinct subset of children with ADHD but that the neurotransmitter glutamate seems to play a big role in some cases. Hopefully, these findings will allow researchers to identify safe and effective treatment strategies for the subset of children with ADHD who have variations in their glutamate-related genes.”
Co-author Dr. Josephine Elia, a child psychiatrist and ADHD expert at Children’s Hospital said, “This research will allow new therapies to be developed that are tailored to treating underlying causes of ADHD. This is another step toward individualizing treatment to a child’s genetic profile.”
About 5.2 million U.S. children ages 3 to 17, seven percent of school-aged children, have been diagnosed with attention-deficit/hyperactivity disorder, according to the CDC.
Symptoms of ADHD include, short attention span and/or hyperactivity and impulsivity. The three types of ADHD include:
-Combined ADHD and is the most common type, which involves all of the symptoms.
-Inattentive ADHD was previously known as ADD, which is marked by impaired attention and concentration.
-Hyperactive-impulsive ADHD, which is marked by hyperactivity without inattentiveness.
ADHD: Signs, Symptoms, Research:
- New Gene Study of ADHD Points to Defects in Brain Signaling Pathways (prnewswire.com)