Zeroing In on 3 Autoimmune Diseases
Genetic Link May Help Explain Diseases From Psoriasis to Lupus
WebMD News Archive
Nov. 10, 2003 -- New discoveries about a set of genes may help
unlock the mystery behind who can get an entire family of diseases from
rheumatoid arthritis to lupus.
Researchers have long suspected that people with a group of
diseases of the immune system known as autoimmune diseases may share a set of
genes that put them at risk for these disorders.
But new research takes them a step closer to identifying which
genes might be responsible for at least three of these diseases: rheumatoid
arthritis, lupus, and psoriasis.
Although the causes of most autoimmune diseases are unknown,
researchers suspect that a combination of genetic susceptibility and
environmental factors may contribute to a person's risk of developing these
Genetic Links for Psoriasis, Rheumatoid Arthritis, and Lupus
In the first study, researchers identified a gene that
increases a person's susceptibility to psoriasis, an inflammatory skin disorder
that affects about 2% of the population. The gene is one that turns switches to
the immune system on and off, and a defective version of this gene has been
found in a significant number of people with psoriasis.
In the second, researchers found a genetic defect that may
increase the risk of rheumatoid arthritis. Rheumatoid arthritis is a
progressive disease that causes the lining of the joints to become inflamed,
swollen, and painful.
Researchers say the genetic influence on rheumatoid arthritis
risk seems especially strong. Siblings of people with the disease have a 2 to
17 times higher risk of developing rheumatoid arthritis themselves compared
with the general population.
A third study showed that a rare genetic variant may play a
role in the susceptibility for the development of lupus, a complex disease of
the immune system that affects virtually all tissues of the body. It commonly
affects women and for most is a mild disorder, but it can cause
life-threatening damage to many organs in others.
Researchers say that these findings build on previous research
suggesting that these diseases may share a common genetic bond, and these
studies provide new clues about how these genes interact to trigger development
of autoimmune diseases.
If further studies confirm these results, researchers may
eventually be able to develop genetic screening tests for certain autoimmune
diseases or develop more effective treatments.