Advances in Dyslexia Genetics-New Insights Into the Role of Brain Asymmetries

Abstract

Dyslexia is a common condition affecting up to 10% school-aged children. There is strong evidence that genetics plays an important role in dyslexia and is expected to be complex in nature. Few specific susceptibility factors have been identified so far, but their functional characterization has provided novel insights into the biology of dyslexia. In particular, they point to an unexpected role of candidate genes for dyslexia in the biology of cilia, cellular organelles required in many processes including the establishment of left-right asymmetries early in development. This observation has brought back into the spotlight the old idea of a link between dyslexia and handedness. Yet much of the genetics contributing to dyslexia remains unexplained. The lack of biological markers, clear diagnostic criteria, and homogeneous assessment strategies are just some of the factors preventing the collection of the cohorts powered enough for large-scale genetic studies. While the technology and methods to generate and handle large-scale data have reached unprecedented potential, the main challenge remains in establishing universal guidelines to collect suitable phenotype information across independent studies. These difficulties reflect the complex nature of dyslexia which is highly heterogeneous and often co-occurs with other neurodevelopmental disorders.

Keywords: Association studies; Brain asymmetries; Cognition; Dyslexia; Genetic mapping; Language; Reading abilities.