Researchers Find Gene Linked to MS, Arthritis

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Researchers Find Gene Linked to MS, Arthritis

Thu Apr 25,10:56 AM ET

By E. J. Mundell

NEW ORLEANS (Reuters Health) -

A study in identical twins

has uncovered a previously unknown gene with strong

associations to both multiple sclerosis (MS) and rheumatoid

arthritis, researchers report.

The finding is " just one more piece of the puzzle " in the

search to find the causes--and, it is hoped--cures for these

two common, debilitating diseases, said graduate student

researcher Carolyn Greene of town University in

Washington, DC. She and her colleagues presented the findings

here Wednesday at the annual Experimental Biology 2002 meeting.

MS and rheumatoid arthritis are both autoimmune disorders,

illnesses where the body's immune system inexplicably attacks

healthy tissue. In MS, immune cells gradually wear away the protective

myelin sheath surrounding nerve fibers in the brain

and spine, leading to increasing neurological and motor

impairment. In rheumatoid arthritis, tissues lining the joints

become the focus of attack, causing patients pain and

disability.

Seeking to find genes linked to MS, Greene and her

co-researchers conducted detailed comparisons of the genetic

make-up of a set of identical twins, only one of whom suffered

from MS. Just such a gene turned up, and was active at a rate

8.5-times higher in the MS-affected twin compared with the

healthy twin. Greene said the gene appears to have been

previously unknown, since it " didn't match to anything " in

GenBank, the human genome (news - web sites) database.

To rule out the possibility that the finding was a fluke,

the researchers then looked for the gene in a group of healthy

individuals and another group of 13 MS patients. As expected,

only the MS group had high levels of gene activity.

The town researchers also tested individuals with

other forms of autoimmune disease for high levels of gene

activity. Five patients with rheumatoid arthritis tested all

had high levels, Greene said. On the other hand, patients with

another autoimmune condition, Crohn's disease, displayed normal

levels of the gene.

Greene stressed that both MS and rheumatoid arthritis are

complex diseases likely to have both genetic and environmental

causes. This discovery, she said, was just one step on a much

longer journey. The next step is to try and determine what role

the gene might play in triggering either disease.