Genetic cause for dyslexia discovered
About five million people in Germany have a reading/spelling disability. Five to twelve percent of all schoolchildren are affected, twice as many boys as girls. The disorder occurs in familial clusters – that was the starting point for the search for the genetic causes.
First, the research team analyzed the implicated DNA region in 137 children with dyslexia and in their parents. The scientists discovered characteristic anomalies, which were confirmed in a second group of 239 affected families. Especially in children with very severe dyslexia, DCDC2 appears to have great significance.
But the exact function of the DCDC2 gene is not yet known. During brain development it probably influences the migration of nerve cells. Signs of disturbed brain development are visible on MRI images of the brains of the affected persons.
The NGFN researchers now want to elucidate as soon as possible exactly which mutations in the DCDC2 gene lead to dyslexia. Probably the gene is no longer correctly regulated, and too much or too little of the protein is produced for which DCDC2 supplies the blueprint. The researchers did not find any indications that the structure or composition of the protein itself was altered. However, dyslexia is considered to be a complex genetic disease. That means that besides DCDC2, probably even other genes play a role, and environmental factors also influence the risk for the disorder.
Website of the scientists involved in this project
Institut of Humangenetik - University Bonn
Life & Brain Center - University Bonn
IMBS - University Lübeck
KJP - University Marburg