Genetic susceptibility to the connective tissue diseases.

Genes important in the connective tissue diseases are being recognized in two basic ways: association studies and linkage analysis. Traditionally, association studies have confirmed a genetic influence in disease pathogenesis, especially in systemic lupus erythematosus, rheumatoid arthritis, juvenile rheumatoid arthritis, and the spondyloarthropathies. One of the strongest associations is with the HLA region. As techniques improve, genome scan studies suggest that multiple genes are involved in each of the connective tissue diseases, with some genes in common that confer an autoimmune susceptibility. Linkage analysis is identifying new candidate genes that will help to explain the etiology of connective tissue diseases.