DNA MARKERS ASSOCIATED WITH GENERAL AND SPECIFIC COGNITIVE-ABILITIES

Multivariate quantitative genetic research suggests a hierarchical mod el of cognitive abilities where genetic effects are largely general, c utting across most cognitive abilities. Some genetic effects, however, are specific to certain cognitive abilities. These results lead to a hypothesis for molecular genetic research: Although most genes associa ted with one cognitive ability will be related to other cognitive abil ities, some genes will be specific to a particular cognitive ability. The current research explored this hypothesis in an analysis of data o n specific cognitive abilities from 86 children from 6 to 12 years of age from a larger allelic association study of general cognitive abili ty. Eight DNA markers were entered simultaneously in separate multiple regression analyses predicting each of four specific cognitive abilit y factors (Verbal, Spatial, Perceptual Speed, Memory), as well as WISC -R subtest scores. Four markers (CTGB33, EST00083, HLA, and SOD2) show ed similar effects across the cognitive ability scales. suggesting tha t they are related to general cognitive ability (g). These association s became negligible when the effects of 'g' (WISC-R IQ) were removed. Three markers (ADH5, DM, and NGFB) continued to be significantly assoc iated with specific cognitive ability scales after the effects of 'g' were removed. Although preliminary, these molecular genetic results su pport the hierarchical model predicted by quantitative genetic researc h.