Dyslexia: From Gene to Brain, What exactly happens?

So, everyone knows that dyslexia is the mixing or emission of symbols or letters in reading. For this to go wrong, there has to be some sort of interference in the signal-transduction pathway, from signal receptors in the eyes to the transduction into the brain. In this case, the part that goes wrong in dyslexia is the brain, more specifically the parts on the left side of the brain used for reading in writing. This makes it impossible for images and sound signals to be translated by the brain into something understandable. The important thing to know is that there are three main ways to get dyslexia. The first type of dyslexia is described as "trauma dyslexia". This occurs when a person receives damage to part of the brain responsible for translating signals. The second type is called "developmental dyslexia". This is caused by hormonal development during the early stages of fetal development. The final type, which will be the focus of this blog, is "primary dyslexia". Unlike the traumatic variety, primary dyslexia is the natural dysfunction of the left side of the brain, rather than damage or injury. Unlike the first two, the effects of this does not fade later in life. Heredity passes this dyslexia to children, meaning that traits for dyslexia are on a gene.

So, what causes such a small gene difference cause such a dysfunction of the brain. Well, genes have been linked to many disorders of the brain, such as leukodystrophies, phenylketonuria, Tay-Sachs disease, and Wilson disease (http://www.nlm.nih.gov/medlineplus/geneticbraindisorders.html). A simple mutation in the base pairs of genes can cause a change, and the emission of a base pair can cause an entire shift in development of the brain. This change can come from the environment or, of course, can be passed down. The gene that develops into the left side of the brain and would cause this mutation is unknown, and research on this disease has led to many theories on what exactly happens to the brain and receptors (ears and eyes) because of this mutation. Of course since this kind of dyslexia is caused by genetics, there is no cure for it if you have primary dyslexia.

So, how exactly do you diagnose dyslexia? It may seem obvious if you're trying to self-diagnose, whether or not you mix up symbols. "Oh, if I'm reading (or hearing) something and it makes sense, then I'm obviously not dyslexic." No. It's not that adults with dyslexia can't read anything without it making sense, it's that they have to strain themselves, which causes most dyslexics to only be able to read at a 6th-grade level. There are some modern tests for dyslexia that analyze your personality (http://www.testdyslexia.com/) as well as ability to comprehend (http://overcoming-dyslexia.com/Adult_Dyslexia_Test.html), but really the only way to truly know, as always, is to seek a professional if you feel as though you, or your child, exhibit some of the symptoms (http://www.medicinenet.com/dyslexia/page2.htm#3whatare)