Genetic association studies in complex diseases.

Genetic association studies are the most frequent type of study performed in the investigation of the genetic basis of complex cardiovascular conditions. While relatively easy to perform, and having previously correctly identified genetic effects subsequently proven to be due to genetic linkage, interpretation of the results of these studies is not always straightforward. Issues such as population stratification, data-driven subgroup analysis, possible absence of linkage disequilibrium between marker and disease locus, and testing of multiple hypotheses are discussed and the likely place for association studies in a strategy involving studies of a variety of designs geared to finding genetic determinants of disease susceptibility is addressed.