Everything Science

This may work for some genetic diseases.

However, while there are genetic indicators for diabetes, which may predispose an individual to develop the disease, more relevant considerations would include age, diet, exercise and smoking habits. And weight, depending on the type of diabetes.

You can only predict an increased risk. More typically hypoglycemia (rather than diabetes which is hyperglycemia) will be passed on genetically and lead to people contracting diabetes due to poor blood sugar control.