Dr. Ezio Bonifacio describes the genetic and environmental factors associated with T1D diagnoses
Researchers are not sufficiently studying type 1 diabetes in minority populations, said Ezio Bonifacio, PhD, professor of diabetes and preclinical stem cell work at the Technical University of Dresden, Germany.
Do we know what genetic or environmental factors “tip the scales” in the development of type 1 diabetes (T1D)? Are some factors more important than others, or is the development due to a combination of factors?
We know a lot more about genetics than about environmental factors, very good genetic regions that tell us a lot about why kids can get autoimmunity and then diabetes. Then we have a whole bunch of others who contribute a bit. So there are probably, I don’t know, 80 regions of the chromosome that contribute a little, some more than others. HLA, which is associated with many diseases related to the immune system, is the main contributor, but we also have the insulin gene itself, which is important in the risk of T1D. Children who have HLA susceptibility and insulin susceptibility have a higher risk. Like I said, we use that, we create scores and we can identify which ones are most likely to leave. On the environment, yes, there is a mixture. I think when we say that someone may have the highest genetic risk, but they’re not sure whether they get diabetes, and even with all the good genes, say, or the bad genes. There must be other factors that come into play and we have known that for a long time it has been difficult to identify one. The virus continues to appear. But we haven’t really found the virus or a specific virus. There are probably a lot of environmental factors that tip it over. Some of them are going to kind of switch it to developing autoimmunity, and then there’s a stage where those kids who have those antibodies end up going into clinical disease. Some take months, others 10 to 20 years. There are probably some environmental factors, again it could be a virus, pushing it to this point.
Can we say why the incidence of T1D appears to be increasing in children from minority groups?
Very good question, and the question actually poses one of our failures. We do not study minority groups enough. I don’t think it’s just a T1D problem. I think this is a problem in general. Personally, I think this is where we need to work a lot more. I think there has been a lot of effort to say that we need to include and particularly study minority groups, but we don’t have enough information. We know that genetically they are slightly different. But they tend to have similar but different proportions of genetic risk. At the level of minorities, we know at least one factor, which leads more to diabetes, and which is linked to lifestyle. Some of the minority groups may have more lifestyles associated with poor health in general, or perhaps obesity. Some of these factors, we know, can make genetic and other factors worse to increase the likelihood of getting diabetes in childhood. There are studies in America actually, a lot of studies in America, good studies in America that have shown this a lot more than in Europe, but it’s clearly an area that requires a lot more effort.