IL-6 gene polymorphism in rheumatoid arthritis, pauciarticular juvenile rheumatoid arthritis, systemic lupus erythematosus, and in healthy Danes.

The restriction enzymes MspI and BglII identify two different two-allele restriction fragment length polymorphisms (RFLP) in the human IL-6 genes of healthy Danes. Co-dominant segregation was demonstrated for both marker-systems and the test for Hardy-Weinberg equilibrium showed no significant deviation from expectations. There is a strong correlation between the two marker systems. The two IL-6 RFLP's were studied in Danish patients with rheumatoid arthritis, pauciarticular juvenile rheumatoid arthritis, and systemic lupus erythematosus. The frequencies of the MspI and BglII marker phenotypes did not differ between healthy controls and the three disease groups. No extra or missing DNA fragments were observed in the disease groups when compared with controls.