Benjamin Smith is not yet 8 years old but already knows precisely why he is at increased risk for developing Type 1 diabetes.
His parents, Jennifer and Larry, each carry a half-copy of a high-risk gene, “and I got the whole” gene, Benjamin said.
Why he has yet to develop the disease despite that genetic risk could provide researchers with an answer for why there is geographic variation and potentially what can be done to stop it.
Benjamin is one of 8,677 high-risk children in an international study called The Environmental Determinants of Diabetes in the Young, based at Georgia Regents University, which recently received a $10 million renewal for another five years. The multicenter study begun in 2003 also includes sites in Florida, Denver and Seattle and in Finland, Germany and Sweden.
Children such as Benjamin were found after screening more than 424,000 newborns for the high-risk genetic trait. They will be followed and provide samples until they reach age 15.
The study already has accumulated a wealth of samples that are being analyzed by laboratories around the world, including genomically at GRU, said a principal investigator, Dr. Jin-Xiong She, the director of the Center for Biotechnology and Genomic Medicine at GRU.
“This is a very exciting moment in the TEDDY study,” She said. “We should have some preliminary answers to the questions we ask in the next 12 months or so.”
Included in that information might be why there appear to be differences geographically. For instance, none of the study children who live in Augusta have developed diabetes, although they make up a relatively small number, She said.
“That in itself is interesting, but we should put this in the bigger context,” he said.
Children in Georgia – and to a lesser extent, in Florida – appear much less likely to develop the disease, even among those carrying the high-risk genetic markers, compared to the other sites in the U.S. or Europe, She said. Though he can only speculate for now, it could be that “certain environmental factors in the (Southeastern) U.S. may be protective against Type 1 diabetes,” he said.
“Our center is very critical in terms of finding out what causes the disease and what prevents the disease from happening,” he said.
Type 1 diabetes is an autoimmune disease in which the immune cells begin to attack insulin-producing cells in the body. She has been intrigued by a potential link to the “hygiene hypothesis,” in which early exposure to things such as bacteria actually help in the development of a healthy immune system; previous research showed infants who lived in a home with dogs had half the rate of allergies.
The bacteria you have a person has, particularly within your the digestive tract, can vary widely from home to home, She said.
“A lot of the microbes are protective, and some of them may cause the disease,” he said. That is part of what the study is doing in sequencing the bacteria from the children.
Though his grandmother and other relatives have developed the disease, Benjamin is the only one among his cousins who carries the high-risk gene, Jennifer Smith said. The family doesn’t indulge in a lot of sugary foods anyway, but they try to be careful with Benjamin, she said.
“I try to do it in moderation,” she said.
She was pleasantly surprised to hear that others like Benjamin are resisting the development of the disease.
“That’s really cool,” Benjamin’s mother said, turning to her son on the couch next to her. “The things you’re doing are making a difference.”
That is why She, the researcher, is grateful for their continued participation.
“Without them, we cannot do it,” he said. “Georgia is important. We need Georgia to figure out what is going on.”