Are MS and Arthritis Genetically Linked?

One more piece of the puzzle in the quest to find the cause?and eventually the cure?for multiple sclerosis (MS) and rheumatoid arthritis (RA) has fallen into place. A study of identical twins has uncovered a previously unknown gene with strong associations with both diseases.

Researchers at Georgetown University in Washington, DC, compared the genetic makeup of a set of identical twins, only one of whom suffered from MS, and found a gene that was active at a rate 8.5 times higher in the MS-affected twin, compared with the healthy one.

The gene appears to have been previously unknown, since it ?didn't match to anything? in GenBank, the human genome database, according to the study. To rule out the possibility that the finding was a fluke, the researchers also looked for the target gene in a group of healthy individuals and in another group of MS patients. Among individuals in the MS group, the gene had high levels of gene activity. In the healthy group, it did not.

Finally, the researchers tested individuals with other forms of autoimmune disease, and 5 patients who had RA all had high levels of gene activity. Curiously, however, patients with Crohn?s disease, another autoimmune condition, displayed normal levels of the gene.