title: Impact of family structure on the power of linkage tests using sib-pair methods.
abstract: This analysis sought to determine the impact of specific ascertainment criteria based upon nuclear family affectation structures. Specifically, we evaluated the predicted and observed proportion of alleles shared identical by descent conditional on the number of affected and unaffected siblings in a pedigree, and compared sib-pair method linkage results under two ascertainment schemes, random vs. selected ascertainment, for this simulated complex genetic disease. These results suggest that samples differing in the composition of affected and unaffected siblings in the family will differ in their power to detect linkage. An effect of sampling scheme on power to map using affected-sib-pair methods should be considered when a reported linkage is not found in another study population.
authors.affiliation: Department of Biostatistics, University of Washington, Seattle, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Goddard
authors.forename: E L
authors.initials: EL
authors.lastname: Goode
authors.forename: L S
authors.initials: LS
authors.lastname: Rozek
authors.forename: G P
authors.initials: GP
authors.lastname: Jarvik
mesh_terms: D005190:Family; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D008126:Lod Score; D008957:Models, Genetic; D015233:Models, Statistical; D012984:Software
chemical_list: D005819:Genetic Markers