I have to agree with previous posters, It is no use worrying where the diabetes has come from or what caused it. We cannot go back and change the past. We can only start with today and plan for the future. It is far more important to concentrate on where you are and the treatments that are available to you be it medicinal or dietary. It is only through doing this that you can help, modify or delay any medical problems that are associated with the diabetes.
Having said all this if you are planning on having children, then I can understand your interest in genetic markers, and if they are carried on a dominant or recessive gene
Good luck