None of the three tested sets showed significant associations with PC1 or IQ-adjusted PC1 [Table S2g,h (Appendix S2)], although the association between PC1 and the steroid-related pathway approached significance ( P = 0.051).
More recently, a genome-wide linkage and association scan using ∼133,000 SNPs, in 718 subjects from 101 dyslexia-affected families, reported a borderline significant association with dyslexia status at rs9313548, near FGF18 (5q35.1), which is a gene involved in laminar positioning of cortical neurons during development (Field et al. 2013 ).
The SNPs showing the largest allele frequency differences between low and high ability groups were further genotyped and tested in an additional sample of 4,258 children, with 10 SNPs finally showing nominally significant association with continuous variation in reading ability (Meaburn et al. 2008 ).