Intelligence is highly heritable and a major determinant of human health and well-being, being linked to numerous aspects of physical and mental functioning. Recent studies have identified 24 genomic loci linked to variation in intelligence, but the vast majority of its underlying genetic influences remains undiscovered. In this study, we conducted a meta-analysis of data from UK Biobank and other large samples in which cognitive testing had been performed to assess general fluid intelligence (total sample of 269,867 individuals). In each sample, we conducted a genome-wide association analysis to find regions of the genome linked to variation in cognitive test performance, and then we meta-analysed the results across samples. By pooling together this data, 205 associated genomic loci (190 novel) and 1,016 genes were found to be related to variation in intelligence, confirming prior studies and dramatically increasing the previously known catalogue. However, these loci still explain only a small portion of the heritability of intelligence, indicating that it is an extremely genetically complex trait with much remaining to be discovered.
The associated genetic variants were spread throughout the whole genome, but especially concentrated in regions related to protein-coding functions and regulation of gene expression, as well as regions that have been conserved between species across evolution. The associated genes are strongly expressed in the brain, specifically in neuronal regions related to memory and decision-making. The results also highlighted strong genetic correlations between intelligence and multiple health-related outcomes, especially psychiatric disorders, and suggested that there are protective effects of intelligence (or the genetic factors related to intelligence) on risk of Alzheimer s disease and ADHD. This study moves forward our understanding the neurobiology of cognitive function as well as genetically related neurological and psychiatric disorders.
|Causes of individual differences in cognitive and mental health
|Genome-wide association meta-analysis in 269,867 individuals identifies new genetic and functional links to intelligence
|26 Nov 2020