Description: A specific region of the human genome appears to be associated with rheumatoid arthritis, European researchers say.

A team from the Karolinska Institute, Stockholm, and elsewhere, conducted genetic analyses of hundreds of rheumatoid arthritis patients.

They found a consistent association between the disease and one region of the genome. This region, on chromosome 9, includes two genes called complement component 5 (C5) and TNF receptor-associated factor 1 (TRAF1).

TRAF1 is involved in inflammatory response, and C5 plays a role in the complement system, involved in defending the body against foreign molecules, the researchers said.

The chromosome region in which these genes are located may be involved in the binding of a protein that modifies the transcription of genes. The researchers also found that one of the alternative markers in this region is associated with more aggressive rheumatoid arthritis.

The findings add to a growing bo