How common are language-based learning disabilities?
According to the International Dyslexia Asssociation and the Learning Disabilites Association of America, about 15% of the population (close to one in seven) has a learning disability. Of the students with learning disabilities receiving special education services, 70-80% have deficits in reading.
Luckily, there is plenty of information on how to address the needs of these children. More information on strategies to help children with learning disabilities is available on LD OnLine and Reading Rockets.