Carrion Castillo, A. 1 , Heister, A. 2 , Naber, M. 2 , van der Leij, A. 3 , Franke, B. 2, 4 , Francks, C. 1, 4 , Maassen, B. 5, 6 & Fisher, S. E. 1, 4
1 Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
2 Department of Human Genetics, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
3 Research Institute of Child Development and Education, University of Amsterdam, The Netherlands
4 Donders Institute for Brain, Cognition and Behaviour, Radboud University, The Netherlands
5 Centre for Language and Cognition Groningen, University of Groningen, The Netherlands
6 University Medical Centre, University of Groningen, The Netherlands
Dyslexia is a common learning disability with a known genetic component. Several candidate genes have been implicated in dyslexia susceptibility, such as ROBO1, KIAA0319, and DCDC2. Associations with variants in these genes have also been reported for a variety of psychometric measures that tackle underlying processes that might be impaired in dyslexic people. In this study, we first conducted a literature review to select single nucleotide polymorphisms (SNPs) in dyslexia candidate genes that had been repeatedly implicated in multiple studies. We then assessed the selected SNPs for association in a well-phenotyped longitudinal dataset: the Dutch Dyslexia Program longitudinal sample. We tested for association with several quantitative traits, including word and nonword reading fluency, rapid naming, phoneme deletion and nonword repetition, and took advantage of the longitudinal nature of the sample to examine if associations were stable across four developmental time-points (from 7 to 12 years). Two SNPs in the KIAA0319 gene were found to be nominally associated with rapid naming, and further analysis revealed that these associations were stable across different ages.