title: Statistical properties of affected sib-pair linkage tests.
abstract: Genetic linkage analysis is a powerful tool for the identification of disease susceptibility loci. Among the most commonly applied genetic linkage strategies are affected sib-pair tests, but the statistical properties of these tests have not been well characterized. Here, we present a study of the distribution of affected sib-pair tests comparing the type I error rate and the power of the mean test and the proportion test, which are the most commonly used, along with a novel exact test. In contrast to existing literature, our findings showed that the mean and proportion tests have inflated type I error rates, especially when used with small samples. We developed and applied corrections to the tests which provide an excellent adjustment to the type I error rate for both small and large samples. We also developed a novel approach to identify the areas of higher power for the mean test versus the proportion test, providing a wider and simpler comparison with fewer assumptions about parameter values than existing approaches require.
authors.affiliation: Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA. ccwu@mdanderson.org
authors.forename: Chih-Chieh
authors.initials: CC
authors.lastname: Wu
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Amos
mesh_terms: D000483:Alleles; D008040:Genetic Linkage; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D006801:Humans; D016013:Likelihood Functions; D016555:Matched-Pair Analysis; D008957:Models, Genetic; D015233:Models, Statistical; D035781:Siblings
chemical_list: D005819:Genetic Markers