CAUSES OF DYSLEXIA

Biological Bases
There cannot be genes for reading, it being a relatively recent cultural invention (just as there cannot be football, farming, or typing genes). However, there can be genetic influences on the behavioural and cognitive traits necessary for proficiency in cultural inventions like reading. It is not surprising then that there are genetic influences on the written language skills. Studies have shown that dyslexia aggregates in families. 25-60% of parents of children with dyslexia also display reading difficulties (46% in fathers and 33% in mothers).

Genetic factors account for the majority of the individual differences in reading ability once children enter school. Shared family factors, such as how much you read to your children, make almost no difference. A number of genes have been identified as being associated with dyslexia and there are others present in groups with dyslexia that are also associated with ADHD and speech disorders. It is therefore unlikely that a single gene or even a set of genes will be found to account for the disorder.

These data do not mean that genes are everything. Genes are expressed (turned on) or modified as a result of experience. For a child to have a dyslexia they likely have to have some level of genetic predisposition coupled with some level of environmental risk (e.g., inappropriate teaching methods). Nor does genetic risk always lead to reading disability, as protective factors within the child's environment (e.g., intensive early reading intervention) reduce the chance that genes will be expressed.

TREATMENTS FOR DYSLEXIA

The type of treatment required depends upon which subtype(s) of dyslexia each student has. For example, a student with phonological dyslexia will require a systematic phonics intervention while a student with surface dyslexia will require a whole-word or "lexical" treatment. Some students may require additional treatments that target vocabulary, grammatical language skills and other aspects of comprehension.

See Understanding Words for an example of the different types of instruction required by a student with dyslexia.

DYSLEXIA & TECHNOLOGY

Many great tools are available to help children with dyslexia and other learning difficulties. This page provides links to blogs written by Dr. Craig Wright that have reviewed useful technology solutions.

Visit the Podcasts, Vodcasts page and Blog page for reviews and information on technology tools that can be used for dyslexia and other learning difficulties.