The genetics of dyslexia: learning from the past to shape the future

It is estimated that up to 70% of the risk of developing dyslexia and of the variability in reading abilities has a genetic origin. This chapter provides an overview of the different methods that have been used to pinpoint the specific genetic factors underlying such risk. Through a chronological perspective, it starts by describing the characterization of a few candidate genes which, for a long time, dominated the field and shaped theories around neuronal migration and cilia biology aimed at explaining dyslexia. The strong heritability for dyslexia provided the basis for molecular genetics studies aimed at pinpointing specific genes. In the last 15 years, genome wide-association studies have become the gold standard method for identifying the genetic factors underlying common multifactorial conditions like dyslexia. The focus of statistical modeling of molecular genetic data has shifted from the analysis of individual markers to the aggregation of multiple single nucleotide polymorphisms using polygenic risk score analysis.