Mody 2 is usually in thin people. It is genetic so you either have the gene or you don't. Diet and exercise is how it is controlled. You are right that type II diabetes is becoming more common among kids, but this is different from MODY 2.
i hate to hear that your son has MODY 2. sadly its becoming more and more common because of childhood obesity in the USA. there is plenty of information on it and it is easily managed.