S26.1: Tests in a case control design including relatives

Abstract

We present a new approach to handle dependencies within the general framework of case control designs in genetic epidemiology. These dependencies arise from relatives being present in the sample thus violating iid assumptions. The theoretical background for data analysis becomes more complex by allowing for this modification. A theorem is proven in a general context characterizing the joint asymptotic distribution of the entries in the associated contingency tables under the null hypothesis of independence of phenotype and genotype at the observed locus. As relevant for applications in genetic epidemiology, the asymptotic distribution of several tests can be derived from our result. In particular, we consider tests on equality of allele frequencies and odds ratios. A simulation study reveals the finite sample behaviour of these test statistics. Our results can also be applied to more general settings in medicine or natural science.