Defective gene could increase diabetes risk

A new study has pinpointed a defective gene that could increase the risk of people developing conditions such as type 1 diabetes, rheumatoid arthritis and lupus. The work, carried out at the Mount Sinai Hospital in the United States, showed that the mutant gene PTPN22 raises the risk for a range of autoimmune diseases.
The research, which was published in scientific journal Nature Genetics, showed that the gene, which usually produces a protein that suppresses immune cell responses, starts to change so that the protein nearly disappears and the immune response increases in strength until it begins to attack its own good cells.
The team used a genetically modified mouse model to copy the genetic defect that can be found in rheumatoid arthritis patients. Once the effects of the missing protein and immune response were shown in the mice, the test was repeated for blood samples from patients with and without rheumatoid arthritis. The PTPN22 gene was seen to lower levels of Lyp/Pep, which stops hyper-immune responses that can lead to the development of autoimmune disorders in healthy cells.
Katherine Siminovitch, a senior investigator at the hospital, commented “Our findings are particularly exciting because the study sets a new precedent for studying arthritis and other autoimmune disorders.”