German Scientists Uncover Dyslexia Gene
June 20, 2006Dyslexia tends to affect family groups, a fact German geneticists were well aware of when they began their search for a gene responsible for the disease. Now, researchers at the National Genome Research Network say they have located the dyslexia gene, known as DCDC2.
The presence of the gene makes it five times more likely for a person to be diagnosed as dyslexic, said the group of scientists, who work out of Bonn, Lübeck and Marburg.
Neural development affected
The gene probably disturbs a person's brain development, the scientists said. People with dyslexia may have difficulty remembering, recognizing, or reversing written letters, numbers and words. They might read backwards and have poor handwriting.
In Germany, some five million people suffer from the disorder. Estimates say 5 to 12 percent of school-age children are affected, with boys affected twice as often as girls. The disability often runs in families, a fact researchers used as the starting point for their studies.
Human genetics expert Johannes Schumacher, one of the researchers from the University of Bonn team, said the discovery of the gene is a first step in finding treatment for the disorder.
Breakthrough discovery
"The unusual thing is that it is one of the first illness genes at all to be found in the area of reading and writing disabilities. Through it, we could see that people who were very seriously affected by this reading and spelling disability could be significantly linked to genetic changes," Schumacher told German public broadcaster WDR.
The research team analyzed the genetic material of 137 children and their parents. They concluded that the gene in question disturbs the movement of fetal nerve cells during brain development.
"We assume that neurons move during the fetal and embryonic stage, and that movement is finished at birth," Schumacher said.
The researchers' findings fit nicely with previous dyslexia research done using magnetic resonance imaging.
"The distinctive features that one could see through functional (MRI) examinations definitely affected areas of the brain localized on the left side of the brain, and which are responsible for speech processing and visual impulses," Schumacher said.
No treatment
While researchers have now found the gene responsible for dyslexia, there is still no treatment. However, "we hope it can help us better understand the processes of cellular biology that lead to dyslexia, and in the future, better understand how this disability develops," Schumacher said..
"And at some point we hope to find a way to begin combating the disability, and to better be able to treat it. And depending on the patient, even take early preventive measures."
However, the development of a drug to combat dyslexia is very far off, Schumacher said.