Genetic epidemiology - Approaches to the genetic analysis of rheumatoid arthritis

The basis of susceptibility to rheumatoid arthritis (RA) is complex, compri sing genetic and environmental susceptibility factors. We have reviewed the available approaches to the investigation of the genetic basis of complex diseases and how these are being applied to RA. Affected-sibling-pair metho ds for nonparametric linkage analysis, linkage-disequilibrium-based approac hes, transmission disequilibrium testing, and disease-association studies a re discussed. The pros, cons, and limitations of the approaches are conside red and are illustrated by examples from the literature about rheumatoid ar thritis.