A weighted test using both extreme discordant and concordant sib pairs fordetecting linkage

Statistical procedures using extremely discordant and concordant sib-pairs have been developed for mapping quantitative trail loci in humans. To impro ve the power of the existing methods, test statistics placing greater weigh t on the more discordant or more concordant pairs are proposed. Because the optimum choice of weights would depend on the underlying genetic model, wh ich is not usually known, a test with simple weights is suggested. This tes t is shown to have greater power than the currently available ones for a va riety of genetic models. Genet. Epidemiol. 20:34-43, 2001. (C) 2001 Wiley-L iss, Inc.