Several groups of medical researchers have for a number of years been studying the complicated genetics of the autoimmune disease lupus in humans and now this massive effort has begun to unravel some of the threads of this often confusing disease, according to studies published this week in the journal Nature Genetics and the New England Journal of Medicine. Two teams of scientists have identified several genes that are linked to lupus, an unpredictable and potentially fatal disease that affects more than 1.5 million Americans and at least five million individuals worldwide.
"The findings of these studies are significant. By identifying specific genes which may contribute to increasing an individual’s risk for developing lupus, it may be possible to develop new treatments aimed at the underlying problem instead of just at the symptoms," said Sandra C. Raymond, President & CEO of the Lupus Foundation of America, the nation’s leading nonprofit voluntary health organization dedicated to finding the causes of and cure for lupus.
In the study published in the journal, Nature Genetics, an international team of investigators looked at over 300,000 genetic variants in a total of 2,566 women with lupus and 4,162 healthy people with no signs of the disease. Dr. David Karp, Chief of the Rheumatic Diseases Division of the University of Texas Southwestern Medical Center in Dallas and Vice Chair of the Lupus Foundation of America Medical-Scientific Advisory Council is excited about the findings. "They confirm in a very rigorous fashion some of the genes we already knew that were risk factors for getting lupus, but they also identified four new genes that are strongly associated with lupus and ten others that are possible risk factors."
In the second study published in the New England Journal of Medicine, researchers using samples from 1,311 people with lupus and 3,340 healthy individuals identified regions on two chromosomes that may contribute to individuals being predisposed to lupus. These findings were replicated in samples taken from another group comprised of 1,650 individuals with and without lupus.
There is a strong genetic (hereditary) component to lupus, yet no one gene causes the disease. Instead, the risk for a particular person is a combination of several genes acting together. In order to study all the genes that could lead to disease, it is necessary to have thousands of subjects -- both people with lupus and people who are healthy.
"These studies will pave the way for more research that will determine just how these genes lead to lupus," says Dr. Karp. "We need to know how the proteins made by these genes act both by themselves and in combination with each other and environmental exposures such as common infectious diseases. We need to learn whether we can use this genetic information to predict who will get lupus, or how severe it might be."
While there is still a long way to go to understand how these genes predispose to disease, least lupus researchers now at least have a hard fact from which to start. Sandra Raymond says the momentum that is building for discoveries in lupus research is very encouraging. "The results of these studies and other recent advances in understanding the origins of lupus give people with lupus, their families and health professionals hope that it may be possible to identify who may be at risk for lupus and prevent the underlying causes of disease activity."