Finding Out Why Fidgety Philip Fidgets
The hyperactive Fidgety Philip in the children’s book “Slovenly Peter”
They are easily distracted, impulsive and hyperactive. They are like Fidgety Philip in the children’s book “Slovenly Peter”, who can’t sit still at the dinner table, rocks on his chair and doesn’t want to listen to what his parents tell him:
Children with this kind of behavior might have an attention deficit hyperactivity disorder (ADHD) syndrome, also called the “Fidgety Philip Syndrome”.
Scientists of the National Genome Research Network have now identified three genetic variants involved in the development of ADHD. The research team headed by Professor Johannes Hebebrand of the University of Duisburg-Essen has studied 329 families in which at least one child was affected by ADHD. They identified a combination of three mutations in the gene for the so-called dopamine transporter closely linked with this syndrome.
“People that have this combination in both copies of the gene have a 2.5 increased ADHD risk. People with only one copy of this variant still have almost twice the risk,” Johannes Hebebrand says, explaining the results of the study. "Of course, this doesn’t mean that everyone who has the genetic variants will automatically get the disease,” Johannes Hebebrand adds. “These genetic variants can be found in 70 percent of ADHD patients. Even healthy people can have mutations in the dopamine transporter gene. Rather, today it is assumed that several gene mutations must occur concurrently for ADHD to result.”
The dopamine transporter pumps the messenger substance dopamine which has been released in the brain back into the nerve cell, where it will be stored until another release occurs. Various studies have shown that this metabolism and possibly also the function of the dopamine transporter is altered in ADHD patients. Methylphenidate, one of the most frequently prescribed substances against ADHD intervenes here: By binding to the dopamine transporter, it blocks it. The present study of the NGFN scientists now provides genetic evidence for the role of the dopamine transporter in ADHD.
ADHD is the most frequent psychiatric disorder among children and adolescents. Boys are affected by ADHD three or four times as often as girls. Based on twin, adoption and family studies, it is now estimated that the cause of ADHD is up to 80 percent genetic. The German Federal Ministry for Education and Research is funding the National Genome Research Network in order to elucidate the causes of such diseases triggered by the interaction of different genetic factors.
Website of the scientists involved in this project
