The dyslexia susceptibility locus DYX2 (chr. 6p21-p22) harbours two candidate genes, DCDC2 and KIAA0319. In 2006, Harold et al. reported evidence for interaction between both genes. Having previously identified a risk haplotype for dyslexia in DCDC2, but not KIAA0319, in German families, we also tested for interaction between this risk haplotype and KIAA0319. We found a nominally significant association for the quantitative dimension "word reading", the core phenotype in the study of Harold et al., which may be considered as supportive evidence.