Genetic epidemiology: disease susceptibility and severity.

Genetic factors are increasingly recognized to have an important contribution to the occurrence of both inflammatory and noninflammatory rheumatic disease. Although identifying the specific genetic mechanisms involved in the rheumatic diseases continues to present considerable challenges, the prospect of identifying individual gene action has been brought closer by a number of recent developments. These include newer approaches to phenotype definition, refinements in statistical tools for analysis, and the advent of newer technologies, including the use of microarrays. In this article, we review some of these developments together with the recent literature on the contribution of both broad and specific genetic factors to the spectrum of rheumatic disease. We also consider contemporary opinions on the potential impact of genetic discoveries to human health.