Scientists Search For Rheumatoid Arthritis Genes
Are some people more prone to developing rheumatoid arthritis? Researchers are mapping the genes that will answer that question.
Genetic Clues to Rheumatoid Arthritis continued...
The gene project started about 10 years ago when the North American
Rheumatoid Arthritis Consortium (NARAC) was formed. Researchers knew only that
genetic factors likely played a role in predisposing people to RA, but they
knew little about the specific genes involved.
With the help of robots and other new tools such as microarray analysis,
which allows researchers to swiftly sort through genetic material, Gregersen
reported last fall that a variant of the gene called STAT4 can boost a person’s
risk for RA or lupus (another autoimmune disease) by 30% to 60%, depending on
how many copies of the gene a person has.
His team also found that variants of two other genes -- TRAF1 and C5 --
might also be associated with an increased risk for RA. And in 2004, the same
team reported that a gene called PTPN2 confers a twofold risk for RA and a
number of other autoimmune diseases.
In the future, genetic research may allow doctors to better pinpoint those
at higher risk of developing complications from autoimmune diseases. Looking
into his crystal ball, Gregersen says that “we will find that some of the genes
predispose people to particular disease manifestations.” This information will
help physicians better predict the course of a disease and improve
Toward Earlier Diagnosis of Rheumatoid Arthritis
But that’s not all. This research will allow doctors to detect diseases
ahead of time -- before symptoms begin. “For RA, there are autoantibodies that
appear years before the development of any symptoms. And we know that if you
have those antibodies, you are at increased risk of developing RA. But this is
still not 100% predictive,” Gregersen says.
Looking at a person’s genetic blueprint can help eliminate some of the
question marks. “This information can help us decide who we should treat
earlier,” he says.
“We could develop some type of algorithm that says this person has a high
probability of developing RA and we should treat them before they develop
symptoms.” That’s just how John H. Klippel, MD, the president and CEO of the
Arthritis Foundation, based in Atlanta, envisions it. “A combination of a known
family history of RA, a genetic profile, and a blood marker could be used to
closely monitor people, and at some point we could decide to intervene before
symptoms ever occur,” he says.