QTL Methodology in Behavior Genetics
In the second chapter of this volume, biometrical models in behavioral genetics are presented. Such models provide the foundation for quantitative trait locus (QTL) analysis. The present chapter specifically deals with applying those models to QTL analysis, in both linkage and association contexts. Until relatively recently, linkage was the preferred method for mapping QTLs. The approach has limited power in detecting small effects, unless an extremely large sample size is available. However, linkage extends over large chromosomal regions and so can be used to localize QTLs of relatively large effects to large segments of DNA. In contrast to association mapping, linkage can be detected without actually genotyping a causal variant or a locus that is in linkage disequilibrium with a causal locus. In this case, linkage disequilibrium implies a correlation between a marker and a causal variant within the population as a whole. With the availability of low-cost single nucleotide polymorphism (SNP) chip-based genotyping technologies, the focus has shifted toward association mapping.
KeywordsQuantitative Trait Locus Association Mapping Quantitative Trait Locus Analysis Reading Disability Behavior Genetic
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