Readingis one of the most important cognitive skills to develop as it lays the foundation for acquisition of other scholastic skills. While skilled reading involves perceptual processes and comprehension of text, this project focuses on processes related to accessing stored information about the meaning and pronunciation of words. Children's phonological memory might contribute directly to vocabulary acquisition (Gathercole, Willis, & Baddeley, 1991); in particular, specific language impairment (SLI) has been related to deficits in verbal short term memory as measured by a nonword repetition task which requires meaningless sequences of speech sounds to be repeated (Newbury, Bishop, & Monaco, 2005). Like reading measures, variation in nonword repetition is heritable, and limitations in phonological short term memory also influence dyslexia(Shaywitz & Shaywitz, 2005). Therefore, our study assesses the genetic influence of single nucleotide polymorphisms (SNPs) on both reading and language measures.

We have undertaken a genome-wide association study (GWAS) of reading and language traits using ~2.5 million SNPs (imputed from the Illumina 610 Bead chip) in 1200 individuals (aged 12 - 25 years). The reading measures include a reading factor derived from the Components of Reading Examination (Bates, et al., 2004), the Schonell Graded Word Reading Test and the National Adult Reading Test. The language measure was the summed score of two non-word repetition tests (Baddeley & Gathercole; Dollaghan & Cambell).

To complete our study we would like to attempt replication of our suggestively significant SNPs from the GWAS (none reach GWAS significance) to confirm whether these SNPs are true findings. The ALSPAC sample is a perfect replication sample because they measure reading in a similar aged sample and non-word repetition (our language measure) at a younger age. We therefore require beta effects, standard errors and p-values for the associations of 42 SNPs (33 reading, 9 language). These results will be included in our publication.

Bates, T. C., Castles, A., Coltheart, M., Gillespie, N., Wright, M. J., & Martin, N. G. (2004). Behaviour genetic analyses of reading and spelling: a component processes approach. Australian Journal of Psychology, 56, 115-126.

Gathercole, S. E., Willis, C., & Baddeley, A. D. (1991). Differentiating phonological memory and awareness of rhyme: Reading and vocabulary development in children. British Journal of Psychology, 82, 387-406.

Newbury, D. F., Bishop, D. V., & Monaco, A. P. (2005). Genetic influences on language impairment and phonological short-term memory. Trends Cogn Sci, 9(11), 528-534.

Shaywitz, S. E., & Shaywitz, B. A. (2005). Dyslexia (specific reading disability). Biol Psychiatry, 57(11), 1301-1309.