Researchers Find Genetic Risks for Many Autoimmune Diseases

Autoimmune diseases that affect millions of people—including  type 1 diabetes, multiple sclerosis, rheumatoid arthritis,  and asthma—which mystifyingly cause the immune system to damage tissues in our bodies, may harbor a complex genetic component, a new study finds. This discovery could prompt better diagnosis and someday, better treatment options. A team of scientists from UC San Francisco, the Broad Institute of MIT and Harvard, and Yale School of Medicine have devised a new mathematical tool to dig deeper into DNA databases, and in the process, they found how certain DNA variations, when inherited, are prone to contribute to disease. The team used its approach to analyze data from earlier studies of 21 different autoimmune diseases, and in so doing, enhanced our knowledge of genetic bases for many of these conditions. They also discovered the specific immune cells that are culprits for the diseases. The researchers developed software and used next-generation sequencing techniques to detect the epigenetic characteristics of specialized immune cells, where gene activity is changed without alterations to the DNA sequence itself within the affected genes. They found that the existence of specific genetic variants in different autoimmune diseases can modify patterns of activity of genes in ways that influence functions of the immune system—even though genetic variants are not within genes. Among other discoveries, the study strongly links the cause of multiple sclerosis to the immune system, and not to genetic variants associated with the nervous system. The scientists note this is in line with new multiple sclerosis treatments that work on the immune system. The findings may help medical researchersmore accurately target therapeutic interventions in autoimmune diseases to dull abnormally fired-up immune responses.