Mentioned in a 23andMe discussion on intelligence. Synonymous Polymorphisms at Splicing Regulatory Sites are Associated with CpGs in Neurodegenerative Disease-Related Genes.[PMID 20077034] rs2289681 Parent Gene: GFAP Importance: 3 Less common allele: T = 14% More common allele: C = 86% My Genotype: Log In Risk Allele: Disease/Trait: Cognition rs2289681 is associated with Cognition (R) . It is reported to have a 0.038 unit increase on Cognitive function. No specific risk allele was identified in the study.