Dyslexia

The word dyslexia is derived from the Greek word, dys (meaning poor or inadequate) and the word lexis (meaning words or language). Dyslexic children seem to have trouble learning early reading skills, problems hearing individual sounds in words, analysing whole words in parts, and blending sounds into words. Letters such as “d” and “b” may be confused. Often a child with dyslexia has a problem translating language into thought (such as in listening or reading), or translating thought into language (such as in writing or speaking). Dyslexia is also referred to as developmental reading disorder (DRD). 

Dyslexia is a problem involving higher (cortical) processing of symbols in the brain. Most children with dyslexia are of normal intelligence; many have above-average intelligence. However, when a child is dyslexic, there is often an unexpected difference between achievement and aptitude. Each child with dyslexia has different strengths and weaknesses, although many have unusual talents in art, athletics, architecture, graphics, drama, music, or engineering. These special talents are often in areas that require the ability to integrate sight, spatial skills, and coordination. 

The underlying cause of dyslexia is not known, although research suggests the condition is often inherited. In 1999, The Centre for Reading Research in Norway presented the first research to study the largest family with reading problems ever known. By studying the reading and writing abilities of close to 80 family members across four generations, the researchers reported, for the first time, that chromosome 2 can be involved in the inheritability of dyslexia. When a fault occurs on this gene, it leads to difficulties in processing written language. Previous studies have pointed out linkages of other potential dyslexia genes to chromosome 1, chromosome 15 (DYX1 gene), and to chromosome 6 (DYX2 gene). The researchers who pinpointed the localized gene on chromosome 2 (DYX3) hope that this finding will lead to earlier and more precise diagnoses of dyslexia. 

Research suggests a possible link with a subtle visual problem that affects the speed with which affected people can read. Anatomical and brain imagery studies show differences in the way the brain of a dyslexic child develops and functions. 

Indicators of dyslexia include: 

• Possible family history of learning disorders 
• Difficulty learning to recognize written words 
• Difficulty rhyming 
• Difficulty determining the meaning (idea content) of a single sentence 
• Writing or arithmetic learning problems 

Common characteristics of a child with dyslexia include problems with: 

• Identifying single words 
• Understanding sounds in words, sound order, or rhymes 
• Spelling 
• Transposing letters in words 
• Handwriting 
• Reading comprehension 
• The spoken language 
• Understanding directions 
• Understanding opposites, such as up/down or early/late 

Social and emotional difficulties often accompany this disorder, as children are unable to meet expectations of parents and teachers and feel frustrated at their inability to achieve their goals. They may have a negative self-image and become angry, anxious, and depressed. 

Demographics: about 15–20 percent of the population of the United States has a language-based learning disability. Of students with specific learning disabilities receiving special education services, 70–80 percent have deficits in reading. With such a high incidence, there is a question as to whether this is really a difference in learning style rather than a true “disability.” The condition affects males more than females, and appears in all ages, races, and income levels. 

Anyone who is suspected to have dyslexia should have a comprehensive evaluation, including medical, psychological, behavioural, hearing, vision, and intelligence testing. The test should include all areas of learning and learning processes, not only reading. Other causes of learning disabilities, such as attention deficit hyperactivity disorder (ADHD), affective disorders (e.g., depression or anxiety), central auditory processing dysfunction, pervasive developmental disorders, and physical or sensory impairments, must be ruled out before the diagnosis of dyslexia can be confirmed. A child of any age may be evaluated for dyslexia using an age-appropriate battery of tests.