Intelligence Genes
A genetic association analysis of cognitive ability using 325 markers for 109 genes associated with oxidative stress and/or cognitive function.
Understanding the genetic underpinnings of cognitive ability and ageing has long been an area of topical interest, particularly in identifying how specific genes may influence cognitive performance and its decline over time. A study by Harris et al.1 looked in-depth into a genetic analysis by association through examining the relationships between cognitive traits and a broad range of genetic markers. By investigating 325 genetic markers across 109 genes associated with oxidative stress and cognitive function, their study aimed to uncover significant associations that could shed light on the biological mechanisms underlying cognitive ability and ageing.
Some significant p-value findings occurred during the research for five distinct single nucleotide polymorphisms (SNPs). The analysis used a battery of different tests to uncover their findings such as the Moray House Test, Raven's Progressive Matrices, the Logical Memory test from the Wechsler Memory Scale-Revised, the Rey Auditory Verbal Learning Test and the FAS test for verbal fluency.
The analysis of genetic associations with cognitive performance revealed various significant p-values, indicating that these associations are unlikely to be chance results. Looking through the study results for the p-significant genes; APP, AGE-R, GLRX, NDUFV2 and NDUFS6, one can see that they vary in regards to efficacy for each test - highlighting that they may be linked to different forms of intelligence.
Looking into each identified single nucleotide polymorphism (SNP) individually, for the SNP in the gene APP, rs2830102, significant associations were observed with the Moray House Test and Raven's Progressive Matrices, showing p-values of 0.003 and 0.016, respectively. These results suggest a strong link between this SNP and the tests measured cognitive outcomes. The Moray House Test assesses verbal reasoning and general intelligence, whilst Raven's Progressive Matrices evaluates abstract reasoning and problem-solving abilities. The significant associations with these tests imply that this SNP may influence cognitive functions related to reasoning and problem-solving.
The SNP AGE-R rs3134943 revealed a significant p-value of 0.036 for Verbal Fluency from the Wechsler Memory Scale-Revised test, suggesting a possible association with the SNP and this cognitive ability. Alongside the AGE-R gene, the SNP GLRX rs4561 and NDUFS6 rs3776141, also exhibited significant p-values for Logical Memory showing 0.003 and 0.011, respectively. To dig into the Verbal Fluency subtest of the Wechsler Memory Scale-Revised test, it evaluates an individual's ability to generate words rapidly within a specific category, which is a key indicator of executive function and language processing skills. These significant p-values for Verbal Fluency indicates that these SNPs may have a role in influencing cognitive abilities related to verbal expression and memory.
The SNP NDUFV2 rs906807 demonstrated a significant association with Raven's Progressive Matrices with a p-value of 0.009. Raven's Progressive Matrices are structured to assess the capacity for logical thinking and the ability to discern non-verbal geometric patterns, making it a robust measure of fluid intelligence which is the ability to think logically and solve novel problems without relying on pre-existing knowledge. Given the significant association with Raven's Progressive Matrices, one might infer that this SNP could have enhanced fluid intelligence reflecting a potential genetic survival or breeding strategy by individuals carrying the mutation.
Some of these SNPs had overlap in their cognitive associations and some showed standalone areas of strength in their presumed ability to help the user cognitively. The strong p-values expressed in the study seem to show a strong feasible association between the gene variants and cognition.
References
A genetic association analysis of cognitive ability and cognitive ageing using 325 markers for 109 genes associated with oxidative stress or cognition by Sarah E Harris, Helen Fox, Alan F Wright, Caroline Hayward, John M Starr, Lawrence J Whalley, and Ian J Deary