Despite no genome-wide significant association, 96 SNPs showed strongly suggestive association with autism risk (Table 1, p<0.0001) and met our initial criteria for follow-up. Among the 96 top hits, 2 SNPs, residing in 5p14.1, had improved p-values in the joint analysis and also had nominally significant association signal in the validation dataset encouraging us to look at this region in more detail. Therefore, we examined every SNP (n=46) genotyped in this region (25830kb to 26100kb) in both datasets regardless of their initial p-value. Analyses of these data revealed a cluster of 19 SNPs including 8 imputed SNPs showing nominally significant association (p<0.05) in the validation dataset (data not shown). Eight SNPs on chromosome 5p14.1 (Table 2) showed improved association signals in the joint dataset. Risk was associated with the same allele for these eight SNPs in both datasets and the p-values became more significant (p-values: 3.24E-04 to 3.40E-06) in the joint analysis, with the most significant p-value coming from one of the top 96 hits rs10038113. The odds ratios for the major alleles ranged from 0.75 to 1.32 (Table 2).
