Yet two factors are important in both. First, you must inherit a predisposition to the disease. Second, something in your environment must trigger diabetes. Genes alone are not enough. One proof of this is identical twins.
Identical twins have identical genes.
Yet when one twin has type 1 diabetes, the other gets the disease at most only half the time. When one twin has type 2 diabetes, the other's risk is at most 3 in 4. Type 1 Diabetes. In most cases of type 1 diabetes, people need to inherit risk factors from both parents. We think these factors must be morecommon in whites because whites have the highest rate of type 1 diabetes.