Korean scientists have identified a connection between attention deficit hyperactivity disorder (ADHD) and a small error in a specific gene. The discovery, published online this week in Nature Medicine, could pave the way for new drugs to treat ADHD, a condition that affects an estimated 5% of school-aged children, making it hard for them to learn.

“This could become a springboard now to study the molecular pathways that cause ADHD in humans,” Huda Zoghbi, a neuroscientist at Baylor College of Medicine in Houston who was not involved in the study, told Nature Medicine.

Several genome-wide scans had recently pointed to chromosome 17 as a hotspot for candidate genes linked to ADHD, but none of these studies had zeroed in on any specific gene targets in this region. So Eunjoon Kim and his colleagues from the Korea Advanced Institute of Science and Technology in Daejeon, South Korea, turned their sights to one such a gene on the short arm of the chromosome encoding the G protein–coupled receptor kinase–interacting protein-1 (GIT1). Researchers had previously linked GIT1 to many cellular functions, including receptor internalization, focal adhesion and cell signaling, but had never implicated the protein in ADHD.

Kim’s team knocked out the GIT1 gene in mice and saw that the animals were more active and displayed impaired learning and memory in a series of behavioral tests. They then validated the findings in people by examining the gene’s sequence in close to 400 Korean children, half of whom were diagnosed with ADHD. They found that a single nucleotide difference was nearly three times as common among youngsters affected by the condition.

“The human results will be useful in the diagnosis of ADHD, and GIT1 knockout mice may be used in exploring the underlying mechanisms and developing novel ADHD medications,” Kim wrote in an email.

In the following video, you can watch as a GIT1 knockout mouse feverishly paces around its cage, with a normal mouse displayed in the cage below for comparison. Also, be sure to check out our video of a mouse model of obsessive compulsive disorder.