Increased variability of stimulus-driven cortical responses is associated with genetic variability in children with and without dyslexia.

•Quantified variability in evoked neural responses of children with and without dyslexia.•A subset of children with dyslexia had significantly higher variability in cortex.•Higher variability observed in auditory and visual domains in multiple reading network nodes.•Risk alleles in KIAA0319 were related to degree of variability in auditory cortex.•Results support unstable neural responses as a mechanism for some cases of dyslexia.