Four independent studies from the United States, Germany, and England implicate two genes in fostering dyslexia. The genes contribute to early brain development.
Dyslexia, a learning disorder that afflicts at least 5 percent of elementary school children, is characterized by difficulties in perceiving sounds within words, spelling and reading problems, and troubles with written and oral expression.
Both of the newly implicated genes normally trigger production of proteins that assist neurons in migrating to appropriate destinations during brain formation. Each gene lies in a section of chromosome 6 that previous studies linked to dyslexia.
"Genetic testing for susceptibility to dyslexia is a realistic possibility in the future," says pediatrician Jeffrey R. Gruen of Yale University School of Medicine in New Haven, Conn.
A team led by Gruen found that variants of a gene known as DCDC2 frequently occur in individuals diagnosed with a serious reading d