ASSORTATIVE MATING AS A STRATIFICATION PROBLEM IN GENETIC ASSOCIATION STUDIES

Genetic association studies have an important role in public health because they help us understand the biological basis of conditions (e.g. diabetes, obesity) that have important public health implications. They can help us develop and direct both treatments and prevention activities. As both Type II diabetes and obesity tend to run in families, it is reasonable to want to ascertain whether a genetic association or linkage exists between a particular allele or alleles and these conditions. Genetic association studies are, generally, the preferred method for detecting genes that are causal variants of complex diseases like diabetes because they have greater power to detect alleles that are susceptible to disease. However, the Case control genetic association studies are known to be prone to false positive associations in the presence of population stratification. We hypothesize that assortative mating in a given population can lead to a form of population stratification and subsequently false positives. We hypothesize that assortative mating in a given population can lead to a form of population stratification and subsequently false positives. We also investigate the role of gene-gene interactions in the presence of assortative mating in producing spurious results. These hypotheses are tested via studies on 10,000 simulated individuals. Our results show that assortative mating does lead to a greater than expected number of false positives as compared to a situation where there is no assortative mating. Our tests on the role of gene-gene interactions also suggest that they contribute to false positives in the presence of assortative mating