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Background: The dopamine D4 receptor gene (DRD4) has been linked to attention deficit hyperactivity disorder (ADHD) and reading disorders. In this study, we examined whether diminished anticipatory dopamine cell firing - typical of the long variant of the DRD4 allele - is related to emergent and advanced alphabetic skills, and whether executive attention is a mediator between this allele and alphabetic skills., Method: We tested alphabetic skills in a normative sample of 159 children in both kindergarten and Grade 1, and executive attention 1 year earlier. Cheek cells were collected and genomic DNA was isolated from the samples using the Chemagic buccal swab kit on a chemagen Module I workstation., Results: Thirty-seven percent of the children were carriers of at least one DRD4 7-repeat allele. Carriers of the long variant scored lower on alphabetic skills, and executive attention appeared to be a mediator of the relation between characteristics of DRD4 and alphabetic skills in kindergarten and first grade., Conclusion: This study shows how a genetic factor which has been shown to relate to variation in attention and regulatory behavior can explain delays in alphabetic skills. A practical implication is that in many cases early interventions should not only target reading skills, but also support children's engagement in tasks., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)

Children showing poor executive functioning may not fully benefit from learning experiences at home and school and may lag behind in literacy skills. This hypothesis was tested in a sample of 276 kindergarten children. Executive functions and literacy skills were tested at about 61?months and again a year later. In line with earlier studies, correlations between both skills were significant at age 5?years, but the predictive value of executive functions on alphabetic skills weakened or disappeared 1?year later. Assuming that executive functions are in development at this age and change has to be taken into account, we applied fixed effects analyses (FEAs) to repeated measures of alphabetic skills and executive functions. FEAs demonstrated that changes in children's alphabetic skills concur with changes in executive functions, thus strengthening inferences about a causal relationship. Executive functions are unstable in the early stages of cognitive development and one-time measures cannot predict their impact on reading 1?year later. Consequences of this new insight are discussed.