Up to 11 (for 2-choice RT) mostly independent SNPs were identified for the measures at a suggestive significance level. For every SNP located in or nearby a gene a NCBI database search was performed to check the gene function and any previously reported associations with cognition-related traits. A number of candidate genes were suggested by this bioinformatics search (see Table 5). Some of these have been associated with psychiatric diseases characterised by cognitive impairment of some sort (e.g., dyslexia, Alzheimer’s disease (AD)), while others are involved in metabolic syndromes which are known to have negative effects on cognition. The association with immune system related disorders is also interesting because a polymorphism in TNF-alpha (which encodes a proinflammatory cytokine) has been associated with processing speed in the elderly (Baune et al., 2008).
