[Methodological issues and new developments in genetic association studies]

Genetic factors are involved in the etiology of many common diseases, even if it is difficult to correctly identify the responsible genetic variations. The main goal of genetic association studies is to identify polymorphisms that vary systematically between people with different conditions of disease. Recent advances in time and cost for genotyping have rapidly moved from a candidate gene approach to genome-wide studies, but the methodological issues remain the same and furthermore increased. One of the major problem is that the genome is large and includes many polymorphic variants which could be found associated by chance. In addiction, complex diseases will require complex analyses in which many variants are assessed simultaneously. To help to distinguish causal associations from spurious ones, restrictive standard for statistical significance or considering polymorphisms which could be a-priori causally associated to disease are needed.