Developmental dyslexia: A review of biological interactions.

The discovery of biological substrates underlying medical conditions is an important step for their better understanding and for the design of appropriate medical therapies. In the case of developmental dyslexia pedagogic treatment may fail, thus creating a group of individuals in whom medical approaches may be entertained. The biological substrate(s) of developmental dyslexia has yet to be specified, although a few clues are beginning to emerge. In this review I consider the issue of cerebral dominance and brain asymmetry, the development of the cerebral cortex and examples of aberrancy, and diseases of the immune system, all of which relate to recent anatomical and epidemiological findings in developmental dyslexia. These discoveries have been able to lead to the creation of testable hypotheses which, after appropriate experimental work, are apt to enhance our current understanding of this and other developmental learning disorders.