[Psychocognitive and psychiatric disorders associated with developmental dyslexia: A clinical and scientific issue].

Abstract INTRODUCTION: Dyslexia is a complex neurodevelopemental disorder that affects 5 to 10% of school-age children. This condition consists in a specific learning disability with a neurological origin. These learning difficulties are unexpected in relation to other cognitive abilities and the provision of efficient classroom instruction. A range of neurobiological investigations suggests that disruption of the parieto-temporo-occipital systems underlies a failure of skilled reading to develop. The observation that dyslexia is both a familial and heritable problem was made early on and was confirmed by twin studies. They also suggested that both genetic and environmental factors are invo…