Presented at the Neonatal Society 2016 Autumn Meeting.
Cyr PEP1, Austin T2, Belteki G2, Amunts L3, Leong V3
1 Dept. Clinical Neurosciences, University of Cambridge, UK
2 Dept. Paediatrics, University of Cambridge, UK
3 Dept. Psychology, University of Cambridge, UK
Background: Dyslexia is a developmental disorder with a strong heritable component that affects up to 15% of the population, but its etiological pathways remain unclear. One leading hypothesis argues that the core deficit in dyslexia is a difficulty with phonological (speech sound) processing and the ability of the brain to phase-lock its neuronal oscillations to speech input (Goswami, 2011). This pilot study hypothesizes that newborns with a parent with dyslexia will be more likely to have dyslexia risk genes and to show reduced phase-locking to rhythmic speech.
Methods: The participants were 5 control infants and 7 familial-risk infants, all less than 7 days of age, and their parents. Two infants were excluded from the phase-locking part of the analysis due to incomplete data collection. The infants were genotyped for 16 SNP’s on DYX1C1, DCDC2, KIAA0319, and ROBO1. They also had an EEG recording, including 20 minutes of silence and 20 minutes of listening to nursery rhymes. The parents’ reading ability and IQ were tested. This study was funded by a grant from the Rosetrees Trust and was approved by the East of England – Cambridge Central Research Ethics Committee.
Results: It was found that there was a significant difference between the high-risk and control infants’ ability to phase-lock their neuronal oscillations to the speech input. This difference in phase-locking was significant in the right temporal area, with high-risk infants showing less strong phase-locking than control infants.
The most promising single nucleotide polymorphism (SNP) was rs333491 on ROBO1, a gene for a protein involved in axons crossing midline during development. An infant’s genotype for this SNP predicted how well their neuronal oscillations in the right temporal area phase-locked to speech better than their family history did. Family history of dyslexia did not correlate with genotype for rs333491, and in fact, did not predict genotype for any of the genes studied.
Conclusion: These results suggest that the ROBO1 genotype and neuronal oscillatory phase-locking could be strong candidates for future investigations as potential biomarkers for dyslexia in neonates, but larger studies are needed to confirm the effect seen here.
Corresponding author: firstname.lastname@example.org
Goswami, U. (2011). A temporal sampling framework for developmental dyslexia. Trends in Cognitive Sciences, 15(1), 3-10. doi:10.1016/j.tics.2010.10.001