Rheumatoid arthritis is the most common type of inflammatory arthritis, affecting about 1 percent of the population, but not much is known about the genes that may cause it. Certain variants, such as HLA-DRB1 and PTPN22, are known to be associated with people who have circulating antibodies to cyclic citrullinated peptides (CCP), a biomarker for rheumatoid arthritis. Researchers wanted to know if they could find any common variants outside the major histocompatibility complex, which contains genes relating to immunity.
A team of researchers from Massachusetts and Sweden conducted a genomewide association study of 397 people with rheumatoid arthritis and a control population of 1,211 people garnered from the Framingham heart study. The researchers succeeded in discovering a variant on chromosome 6 associated with RA. They then replicated their finding in an additional study.
The authors also showed that their result was different from a variant discovered by the British Wellcome Trust Case Control Consortium even though the variants were located very close together on the genome.
More: To read an abstract of this paper on PubMed, a medical database, click here.