title: Asymptotic power of likelihood-ratio tests for detecting quantitative trait loci using the COGA data.
abstract: We investigated the asymptotic power of the likelihood-ratio test for detecting linkage to a quantitative trait locus (QTL) using the data set from the Collaborative Study on the Genetics of Alcoholism (COGA). Assuming a total trait heritability of 50% as determined for the COGA Cz P300 phenotype, we determined the minimum QTL heritability required at each point in the genome to achieve 80% power to detect linkage with a lod of 3.0. We find that there are regions of the genome where it is not possible to detect a QTL of any effect with 80% power, and that the overall minimum detectable QTL heritability for the COGA data is 0.35-0.40.
authors.affiliation: Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas 78245-0549, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Williams
authors.forename: J
authors.initials: J
authors.lastname: Blangero
mesh_terms: D000437:Alcoholism / Q000235:genetics* / Q000503:physiopathology; D016009:Chi-Square Distribution; D002894:Chromosomes, Human, Pair 4; D002896:Chromosomes, Human, Pair 6; D018913:Event-Related Potentials, P300; D008040:Genetic Linkage; D005819:Genetic Markers; D005820:Genetic Testing; D006801:Humans; D016013:Likelihood Functions; D008126:Lod Score; D019655:Quantitative Trait, Heritable
chemical_list: D005819:Genetic Markers