Feb. 16, 2010 -- A newly discovered genetic link may offer new information on the causes of attention deficit hyperactivity disorder (ADHD) as well as help determine who might best respond to treatment.
Researchers have found that a genetic variant on the latrophilin 3 gene (LPHN3) is associated with ADHD in several different populations. Previous studies have also shown that this gene plays a role in how people respond to the stimulant medications often used to treat the childhood behavioral disorder.
"It is very intriguing that the same variant (SNP marker rs6551665) associated with susceptibility to ADHD is also associated with response to stimulant medication," write researcher M. Arcos-Burgos of the National Human Genome Research Institute at the National Institutes of Health in Bethesda, Md., and colleagues in Molecular Psychiatry. "This opens a window for the evaluation of molecular substrates of ADHD and development of new drugs targeting new genes and brain pathways involved in ADHD."
Although several other genes have been linked to ADHD in previous studies, few of these linkages have been confirmed by replication in other populations.
In the study, researchers showed an association between LPHN3 in an isolated population in Colombia and then were able to replicate those results in five different populations from other areas of the world, including Germany, Norway, Spain, and the U.S.
Further brain testing results were also able to confirm this connection by showing that LPHN3 is expressed in brain regions involved in attention and activity as well as how the brain responds to ADHD stimulant medication treatment.
Researchers say the results could help identify people who are susceptible to ADHD and those who would be more likely to respond to stimulant medications as a part of their ADHD treatment.