In general terms, we may conclude that type 1 diabetes has a very strong genetic influence as to its onset, but it is not all genetic that contributes to the onset of type 1 diabetes. We may disconsider cultural factors as they grew up together in the same household.
When considering monozygotic twins we have the closest case scenario to two people with the exact same genetic information (clones), which leads us to think that if the concordance rate for this type of cases is of 73% then the genetic background does have a very important weight. Notwithstanding this consideration, onset of type 1 diabetes is not limited to the basic genetic information but might be related to small habits, such as exercise, food eating, and minor genetic mutations.
When considering dizygotic twins, we are before normal siblings that share a lot of genetic information but also differ much. The fact that they grew up in the same household during the same years helps understand that the concordance of 11% on the onset of type 1 diabetes is probably given by the genetic information that these twins still share as siblings.
