Developmental reading disorder

Alternative names:

dyslexia

Definition:

A reading disability resulting from a defect in the ability to process graphic symbols.

Causes, incidence, and risk factors:

There are about 2 to 8% of elementary-age children that have some degree of reading disability. Developmental reading disorder (DRD) or dyslexia is not attributable to eye problems but instead is a defect of higher cortical (brain) processing of symbols. Children with DRD may have trouble rhyming and separating the sounds in spoken words. These abilities appear critical in the process of learning to read.

Initial reading skills are based on word recognition. More developed reading skills require the linking of words into a coherent sentence (thought). DRD children may be unable to form images from the meanings of the words or to process the words into an idea which is understandable. At this level, reading may fail at its primary function, which is to convey information.

Dyslexia or developmental reading disorder may appear in combination with developmental writing disorder and developmental arithmetic disorder. All of these processes involve the manipulation of symbols and the conveyance of information by their manipulation. These conditions may appear singly or in any combination.

Other causes of learning disability and, in particular, reading disability, must be ruled out before a diagnosis of DRD can be made. Cultural and educational shortfalls, emotional problems, mental retardation, and diseases of the brain (for example AIDS) can all cause learning disabilities.