What Can Genetic Testing Reveal About Autoimmune Disease?

Autoimmune diseases affect as much as 3 to 5 percent of the U.S. population, according to MedscapeCME. They result from impaired immune system functions that mistakenly attack the body's own cells and tissues. Genetic testing research can reveal which genes and chemical pathways create autoimmune conditions. In doing so, new treatment approaches may be uncovered.

Autoimmune Conditions

• Multiple sclerosis, rheumatoid arthritis, type 1 diabetes and lupus are all classified as autoimmune disease conditions. And while they may share few similarities in terms of the bodily systems involved, the body's immune system functions play a pivotal role in their development, according to MedscapeCME. Disease researchers look to understand the genetics that underlie autoimmune conditions, which were once thought to be gene-specific in origin. According to Nature Reviews, ongoing research studies may uncover specific genetic pathways that give rise to several different autoimmune conditions.

Immune System Functions

• The immune system operates on a cellular level through the presence of T cells throughout the body. T cells are designed to spot potential threats or germs and eliminate them before they spread, according to MedGadget. Another set of cells--regulatory T cells--monitors the other T cells to ensure they don't attack the body's own cells and tissues. Autoimmune diseases develop when the body's regulatory T cells are unable to monitor T cell activities. Because most cells in the body have their own set of DNA materials, genetic testing is able to examine how T cell and regulatory T cell genes behave in cases where an autoimmune condition is present.

Master Genes

• Genetic testing studies conducted in 2007 by the Whitehead Institute and the Dana-Farber Cancer Institute uncovered another set of genes that regulate T cell functions. Known as master gene regulators, the Foxp3 genes regulate all T cell activities and appear to play a part in manufacturing T cells, according to MedGadget. A breakdown in the Foxp3 gene results in cell damage caused by rampant T cells attacking the body's own cells and tissues. Ongoing research hopes to develop methods for manipulating Foxp3 cell functions. In doing so, the development of new treatment therapies designed to cure autoimmune diseases may be possible.

Gene Targets

• Genetic testing done by the Dana-Carver Cancer Institute set out to locate which genes within DNA materials were influenced by Foxp3 activities, according to MedGadget. In total, 30 genes appeared to be regulated by the Foxp3 master gene. One of these genes, called Ptpn22, is known for its role in type 1 diabetes, lupus and rheumatoid arthritis. These results reveal how related genes may give rise to autoimmune diseases in general, rather than gene-specific origins for each disease. By identifying existing relationships between genes and how the immune system functions, researchers hope to one day control how the immune system responds when treating autoimmune conditions.

Pathogenic Pathways

• The discovery of gene-based origins for autoimmunity in general may account for cases in which individuals develop multiple diseases at once, according to Nature Reviews. In effect, researchers are able to cluster seemingly unrelated conditions into families based on the type of gene that triggers them. Diseases found to be susceptible to certain genetic makeups may in turn reveal specific chemical pathways responsible for gene development and impairment. In tracing these pathways from gene variations on through to the mechanisms that produce disease conditions, researchers can develop a type of circuitry map that predicts where, why and how an immune response occurs.