Quantitative trait loci for IQ and other complex traits: single-nucleotide polymorphism genotyping using pooled DNA and microarrays


*I. Craig, Social, Genetic and Developmental Psychiatry Centre, King's College Londan Institute of Psychiatry PO82, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. E-mail: i.craig@iop.kcl.ac.uk


Similar to other complex traits, it is likely that many DNA polymorphisms of small effect size [quantitative trait loci (QTLs)] are responsible for the high heritability of intelligence, in addition to many rare monogenic disorders known to contribute to lowered intelligence. We review the current status of approaches to identify QTLs associations for intelligence employing genome-wide strategies using pooled DNA from many individuals and evaluate the innovative approach of microarray analysis to genotype DNA pools for large numbers of single nucleotide polymorphisms.