title: A combined test of linkage heterogeneity.
abstract: This paper focuses on the problem of testing for heterogeneity once linkage is established. In an investigation of genetic linkage, Morton first proposed a general purpose test to detect heterogeneity in the recombination fraction. Two more commonly used tests of linkage heterogeneity are the admixture test (A-test) of Smith, Ott, and Risch and Baron, and the B-test of Risch. All are likelihood-ratio tests, but they differ in the models specifying the heterogeneity. A new test of heterogeneity in the presence of linkage is presented here. I propose a mixture model of heterogeneity, which allows the recombination fraction to vary among families, as does the B-model, yet also allows some families to be unlinked, as the A-model does. This model contains the A and B models as special cases and thus allows a direct test (D-test), which can provide justification for choosing one of these extremes.
authors.affiliation: Department of Statistics, University of California, Berkeley 94720.
authors.forename: D R
authors.initials: DR
authors.lastname: Goldstein
mesh_terms: D005190:Family; D008040:Genetic Linkage; D005826:Genetics, Medical / Q000379:methods*; D006801:Humans; D008957:Models, Genetic; D015233:Models, Statistical; D011995:Recombination, Genetic