A specific version of a gene that encodes the protein GIT1 in the brain is linked to attention deficit hyperactivity disorder (ADHD) in humans, reports a paper online this week in Nature Medicine.
ADHD is characterized by hyperactivity and deficits in learning and memory, affecting both children and adults.
Eunjoon Kim and colleagues find that one GIT1 polymorphism ― version of the gene ― increases the risk for ADHD in humans, probably by reducing the expression of the GIT1 protein. GIT1-deficient mice exhibited ADHD-like behaviors, which were alleviated with psychostimulant drugs used to treat human ADHD. The mice also showed deficits in inhibitory neurotransmission, suggesting that this could be one mechanism by which behavioral deficits are observed in ADHD individuals with the disease-linked GIT1 polymorphism.