Written by: Stephen Hsu
Primary Source: Information Processing
This is a follow up to earlier papers by the SSGAC collaboration — see First GWAS Hits For Cognitive Ability and SNPs and SATS. Effect sizes found are typically ~ 0.3 IQ points. Someone with 50 more good variants (similar to these) than the average person would be about 1 SD above average in IQ.
Note among the authors names like Pinker, Visscher, Plomin, McGue, Deary, etc. Thank god it wasn’t the sinister Chinese who got there first! For more on this topic, including the status of the BGI study, see Genetic Architecture of Intelligence (arXiv:1408.3421).
Common genetic variants associated with cognitive performance identified using the proxy-phenotype method (PNAS, doi: 10.1073/pnas.1404623111)
We identify common genetic variants associated with cognitive performance using a two-stage approach, which we call the proxy-phenotype method. First, we conduct a genome-wide association study of educational attainment in a large sample (n = 106,736), which produces a set of 69 education-associated SNPs. Second, using independent samples (n = 24,189), we measure the association of these education-associated SNPs with cognitive performance. Three SNPs (rs1487441, rs7923609, and rs2721173) are significantly associated with cognitive performance after correction for multiple hypothesis testing. In an independent sample of older Americans (n = 8,652), we also show that a polygenic score derived from the education-associated SNPs is associated with memory and absence of dementia. Convergent evidence from a set of bioinformatics analyses implicates four specific genes (KNCMA1, NRXN1, POU2F3, and SCRT). All of these genes are associated with a particular neurotransmitter pathway involved in synaptic plasticity, the main cellular mechanism for learning and memory.