title: A method for identifying genes related to a quantitative trait, incorporating multiple siblings and missing parents.
abstract: When studying either qualitative or quantitative traits, tests of association in the presence of linkage are necessary for fine-mapping. In a previous report, we suggested a polytomous logistic approach to testing linkage and association between a di-allelic marker and a quantitative trait locus, using genotyped triads, consisting of an individual whose quantitative trait has been measured and his or her two parents. Here we extend that approach to incorporate marker information from entire nuclear families. By computing a weighted score function instead of a maximum likelihood test, we allow for both an unspecified correlation structure between siblings and "informative" family size. Both this approach and our original approach allow for population admixture by conditioning on parental genotypes. The proposed method allows for missing parental genotype data through a multiple imputation procedure. We use simulations based on a population with admixture to compare our method to a popular non-parametric family-based association test (FBAT), testing the null of no association in the presence of linkage.
authors: National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
authors: Emily O
authors: EO
authors: Kistner
authors: Clarice R
authors: CR
authors: Weinberg
mesh_terms: D000483:Alleles; D003198:Computer Simulation; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D016015:Logistic Models; D008957:Models, Genetic; D009679:Nuclear Family; D010290:Parents; D010375:Pedigree; D040641:Quantitative Trait Loci / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D035781:Siblings