Dyslexia Cause

Dyslexia is the general term used to describe a common learning disorder in which reading ability is impaired due to difficulty recognizing the sounds made in speech and how those sounds relate to letters and words. The condition is also referred to as specific reading disability.

Children affected by dyslexia find it difficult to identify root words, which makes it difficult for them to determine the order in which letters should follow each other in words. Children with dyslexia may have normal vision and intellectual ability, meaning the condition can often go unnoticed and undiagnosed well into adolescence and even adulthood. Most children who have dyslexia can go on to perform well at school if they are provided with emotional support, tutoring and educational programmers tailored to their specific needs. A diagnosis of dyslexia is based on intellectual, psychological, educational, medical, speech and language assessments and the condition is managed through educational programmes that teach strategies for word recognition.

Experts now believe that aural as opposed to visual problems are the main factors at play in reading disabilities. The ability to discriminate, blend, memorise and analyse sounds is impaired, which can affect the understanding and production of the written word.

The exact cause of dyslexia is not clear, although the condition is generally thought to run in families. Other factors have also been identified that may contribute to the severity of the condition.

Genetic predisposition

Dyslexia appears to be an inherited condition and children with a family history of learning reading disabilities are more likely to develop dyslexia than children without such a family history.

Researchers have identified six genes that may influence the risk for dyslexia. Four of those genes are thought to be involved in an early stage of the brain formation process called neuronal migration, which leads to the development of specialized brain areas. Most experts agree that dyslexia is associated with dysfunctions in left-hemisphere brain areas that are involved in language comprehension (the Wernicke motor speech area) and sound/speech production (the Broca motor speech area).

Acquired Dyslexia

In a minority of cases, dyslexia develops after birth, most commonly as a result of stroke, brain injury or some other form of brain trauma.

Phonological processing

Phonological processing refers to our ability to understand how words are made up of smaller units of sounds or “phonemes.” As infants, people have a natural ability to recognize words, which helps them to acquire language. However, these words are often recognized as one sound rather than broken down into component sounds. For example, the word “refrigerator” will become recognized as having a certain sound and does not require breaking down into the components “re,” “fri,” “ger,” etc. in order for the child to understand it. This is not the case, however, when a child is learning to read or write.

The development of reading and writing skills depends on a child’s ability to identify letters, assemble them into phonemes and use those phonemes to make up or interpret a word (phonological processing). Brain scans suggest that the cause of dyslexia is rooted in a diminished ability to process words in this way, due to alterations in the development and therefore function of certain parts of the brain.

Treatment options

There is no cure for dyslexia and interventions to help people with dyslexia are designed to improve how they cope with the condition and to enhance their skills in reading and writing. The earlier a child is diagnosed with dyslexia, the sooner they can receive support and the more likely they are to eventually see an improvement. A teacher trained in teaching dyslexic children uses a range of strategies to help the child enhance their reading ability. The techniques usually involve helping the child to tap into their sense of touch, hearing and vision. For example, some children find that using their finger to trace the shape of a letter enables them to process data in a more effective way.

A dyslexic child is helped to improve the following:

• Recognition and understanding of phenomes.
• Reading aloud
• Reading comprehension
• Building vocabulary

Psychologists and teachers also emphasise how important it is to ensure the child maintains a good self-esteem and self-image and to remind the child that although reading and writing may be problematic, dyslexia is a condition that affects millions of people across the globe who have still managed to achieve their goals in life.

Further Reading

• All Dyslexia Content
• What is Dyslexia?
• Dyslexia Symptoms
• Dyslexia Theories
• Dyslexia Management

Written by

Sally Robertson

Sally has a Bachelor's Degree in Biomedical Sciences (B.Sc.). She is a specialist in reviewing and summarising the latest findings across all areas of medicine covered in major, high-impact, world-leading international medical journals, international press conferences and bulletins from governmental agencies and regulatory bodies. At News-Medical, Sally generates daily news features, life science articles and interview coverage.