Causes of Dyslexia

Studies show there may be some genetic tie to dyslexia.  According to Julia Wilde the reporter to DNews Channel (2015), some dyslexics with the deletion of the DCDC2 gene have trouble detecting certain types of visual movement.  Others studies have found that some dyslexics, who have a mutation of the ROBO1 gene, have a weakening of the auditory pathways between the two parts of the brain, the visual center and prefrontal lobe.  Other environmental contributors could be less reading by individuals means less grey matter in those areas of the brain that are involved in reading. Others argue it is a phonological deficit or more precisely, difficulty processing phonemes. To sum up the report, there seem to be numerous causations and issues for what we generally describe as dyslexia.
Watch What Causes Dyslexia:  

The Sage Journal article Teaching Literacy with a Multisensory Approach, written by Kelly and Phillips (2014) provides more in depth analysis.  I took pause at this particular aspect.

“Screening undertaken as part of the ‘No to Failure’ Project in England (Dyslexia–SpLD Trust, 2009) found that 21 percent of children of primary school age may have literacy difficulties which could be described as dyslexia. This is similar to the figures reported in the USA (Shaywitz et al., 2008), although these may include other ‘poor readers’”. My concern is that Kelly and Phillips both acknowledge the importance of having this data and attest that these numbers are “valuable information for policy makers, schools, and local authorities when planning teaching and resource allocation” (p.9).  Yet the authors then site the flaws in the data particularly when citing China’s variance in 2 studies done showing either 1% or 10% of the population has dyslexia. The authors then cite a research report by the Dyslexia SpLD trust that uses the word may all of which demonstrate the lack of statistical and accurate data about the numbers of individuals with dyslexia and not just those with reading difficulties.   

Kelly and Phillips demonstrate that there is much more consensus about the causes of dyslexia.  “Olson and Byrne (2005) suggested that at least 50 per cent of the variance could be explained by genetic factors and the remainder by environmental factors. Snowling (2013) supports the view that dyslexia is the outcome of multiple risk factors both genetic and environmental and also Van Bergen et al. (2014) suggest that we should consider the cognitive profile children inherit from their parents” (p. 13).  The genetic causes show variances in several genes that affect different parts of the brain as well as the neural transmitters. This would corroborate the assertion that dyslexia may be a catch all phrase for several types of cerebral variances. These variances in causes show how dyslexics are all challenged in different ways and while each variance makes reading harder they may each come with a boost in one cerebral area.

While we wait for science to prove the diversity of causes there are two area in which we as teachers can focus.  Lack of access to reading, an environmental factor that inhibits the growth of gray and white matter needed to foster reading.  The second is to focus our efforts on the strategic implementation of reading instruction that would meet their needs.

Works Cited:
DNewsChannel. “What Causes Dyslexia?” YouTube, YouTube, 16 Nov. 2015, www.youtube.com/watch?v=ROPW0R54dgE.

Kelly, K., & Phillips, S. (2014). The contributions of dyslexia research to the development of a multisensory teaching programme. In Teaching literacy to learners with dyslexia: A multi-sensory approach (pp. 7-34). Sage.