Rheumatoid arthritis (RA) is caused by a complex set of environmental and genetic factors. Currently, only a small number of the genes that increase a person’s risk of developing RA have been identified. Discovering additional genes that control RA would help us to understand what causes the disease and potentially how to more effectively treat or even prevent arthritis.

Dr. Johnsen will use a unique group of mice to help find the genes controlling inflammatory arthritis. These mice have been extensively bred for over 50 generations, creating mice with a more diverse genetic background than standard mouse strains. By treating these mice to develop arthritis, Dr. Johnsen will be able to correlate the presence of a particular DNA sequence at a specific location on the genome with the severity of the arthritis. This will identify the location of the genes that are controlling arthritis in these animals. Ultimately, Dr. Johnsen will demonstrate the effect of these candidate genes on arthritis by developing mice that are deficient in these genes, then determining their susceptibility to arthritis.

Dr. Johnsen expects to identify new genes that control arthritis in the mouse. Given the similarity of the mouse model with human RA, it is likely that these genes will also play a significant role in the human disease. Finding genes controlling susceptibility to RA will enhance understanding of how the disease works. In addition, these studies have the potential to identify new targets for therapies in human patients.