title: ASP--a simulation-based power calculator for genetic linkage studies of qualitative traits, using sib-pairs.
abstract: An easy-to-use, simulation-based power calculator (ASP) for linkage analysis using sib-pair designs (concordant or discordant) has been developed and made publicly available via the Internet. The program employs a diallelic model for the trait locus, at which parental/offspring genotypes are simulated, assuming Hardy-Weinberg equilibrium in the parental generation. Genotypes at a linked multiallelic marker locus are simulated conditional upon the inheritance pattern at the trait locus, allowing for recombination. Marker genotypes are tested for non-Mendelian identity-by-descent sharing, using both an unrestricted and a restricted likelihood ratio test, the latter representing an extension of the "mean test" from fully to partially informative families. The power of user-defined datasets is estimated by the number of simulations giving significant results at varying type I error levels.
authors.affiliation: Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XN, Wales, UK. krawczak@cardiff.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Krawczak
mesh_terms: D003198:Computer Simulation; D030342:Genetic Diseases, Inborn / Q000235:genetics*; D008040:Genetic Linkage; D020407:Internet; D008957:Models, Genetic; D015233:Models, Statistical; D009679:Nuclear Family; D012984:Software