Dyslexia is a form of learning disability that affects how a person reads and spells words.
The symptoms of dyslexia can range from mild to severe and can lead to difficulty with certain parts of reading, writing and speech. In particular, a person with dyslexia may experience difficulty with the following:
- Phonological awareness - This refers to a person’s ability to understand how a word is comprised of smaller units of sound. This is essential for spelling and reading. For example, a child with dyslexia may not understand how replacement of the letter “m” in the word “men” with the letter “t” makes it “ten.”
- Verbal memory - Verbal memory refers to the ability to recall verbal information such as a short list of instructions or a few items on a shopping list.
- Rapid serial naming - This refers to a person’s ability to name numbers, colours or objects as quickly as possible.
- Verbal processing speed - Verbal processing speed refers to how long it takes a person to understand and recognise information such as numbers and letters. For example, a child with dyslexia may not be able to write down a telephone number they are told or may have difficulty turning to a particular page number when instructed to do so.
Dyslexia does not affect a person’s intelligence and children with all levels of IQ can be affected by the condition. A dyslexic child’s ability to read or write is determined by the severity of their condition rather than by their intelligence level.
Dyslexia is one of the most common forms of learning disability. Around 10% of all people in the United Kingdom have some degree of dyslexia. The exact cause of this condition is not known but it is generally thought to run in families. Research has identified six genes that may contribute to the development of dyslexia, although the condition is thought to be caused by a combination of factors.
Diagnosis and management
Dyslexia may be difficult to diagnose when a child is very young but the condition is generally diagnosed based on the problems faced by a child as they begin to learn the letters of the alphabet and start to use words.
The treatment approach varies, depending on the severity of the condition. There are a range of educational programmes and interventions available to help improve reading and spelling ability and the earlier these interventions are adopted, the more chance the child has of improving these abilities. The majority of children respond well to interventions and go on to progress in their learning, but other children continue to experience reading and writing difficulties and will require more intensive and longer term support.
Reviewed by Sally Robertson, BSc