Gene Study Probes 7 Common Diseases
Disease Genes Found to Be Risk Factors, Not Fates
The Genetics of Common Diseases continued...
If the diseases are common, so are the genes that affect them. Nearly everybody -- at least everybody in Britain -- carries one or more of the genes identified in the study.
"This is very different from rare mutations that always cause disease; the genes we have discovered are very common. All of us have them; all of us have more or less susceptibility to diabetes, for example," University of Cambridge researcher John A. Todd, PhD, said at the news conference. "This means we can study healthy people who haven't developed diabetes yet, and see what factors alter those characteristics.
"That is what is exciting about common genes," Todd added. "These genes are completely dominated by environmental effects. Now we can actually work out what environmental factors are altering the common genetic characteristics."
New Insights: Type 1 Diabetes
Todd's subgroup looked for genes linked to type 1 diabetes. Genes linked to this disease, they found, affect immune regulation.
The message is that type 1 diabetes is a disease of the immune system where there is innate destruction by the cells of your own immune system of the cells that make insulin.
"Type 1 diabetes is a dysregulation of the immune system," Todd said. "These new genes, and the genes that we have known before, begin to give us a clue as to what has gone wrong. Our task in the next 10 to 15 years is to understand that and to turn the immune system away from this and toward healthy function."
New Insights: Crohn's Disease
University of Cambridge researcher Miles Parkes, FRCP, led the group that studied the genomics of Crohn's disease. Crohn's disease is a type of inflammatory bowel disease.
A major puzzle in Crohn's disease has been whether the condition is caused by infection with unusual bacteria or simply by an abnormal immune response to the bacteria that normally live peacefully inside our intestines.
"The completely unexpected finding is that Crohn's disease is associated with a gene that affects how the body deals with bacteria that have got inside human cells," Parkes said at the news conference. "Prior to these genetic analyses, we had no idea this would be important.
"We are already aware of treatments that affect this pathway," Parkes added. "We can now begin to study these drugs in relation to Crohn's disease."