Local researchers hope studying the DNA of identical twins could help us all.
Avera has the largest twin registry in the world. It's looking into how an identical twin's DNA could provide critical clues into diseases like cancer.
Eight-year-olds Connor and Colin Coleman both dream of playing football in the NFL, but that's where some of their similarities end.
"Colin has more of the wittier, jokester personality, and Connor is more of the quiet, kind of aggressor," mother Shannon Coleman said.
But as identical twins, their DNA is nearly the same.
"If they have the same DNA, you'd think they'd have the same risk of developing a disease. Unfortunately that's not the case, so there must be an environmental or nurture factor involved with all of that," Scientific Director of Avera Institute for Human Genetics Dr. Gareth Davies said.
Researchers at the Avera Institute for Human Genetics are studying the genetics of identical twins. They hope to figure out what causes complex, but common, diseases: genes or the environment.
"These types of diseases--behavioral disorders, Type 1 diabetes, heart disease, many cancers--are a geneticist's nightmare because there are so many genes and environmental factors," Davies said.
But by having samples of twins with almost identical DNA, it's easier to solve the puzzle, especially when one twin develops a disease and the other doesn't.
"We try to tease apart the genetics and the environment and which genes are involved and environmental factors are involved also," Davies said.
Right now, they have around 20,000 DNA samples of twins stored here and are expecting another 10,000 soon.
Researchers hope that if they can better figure out what's causing complex diseases, more people can take steps to prevent serious health issues.
"We all have family history of certain diseases. My family has a history of heart disease for example. If we can tease apart those genetics and that environmental factor, we can maybe reduce our risk and educate ourselves," Davies said.
And if researchers can tackle what causes complex diseases, Shannon thinks it could help her sons lead healthier lives.
"If he's at increased risk for cardiovascular disease, is he going to be too?" Shannon said.
All of the DNA samples actually come from the Netherlands. Avera is partnering with a University in Amsterdam for the study.