The first step in diagnosing MODY is having a blood sugar test. If the results show high levels of sugar that indicate diabetes, your doctor has to figure out if you have MODY or another type of diabetes. Getting the correct diagnosis is important because treatment of MODY can be different than treatment for type 1 or 2 diabetes.
Blood tests can help your doctor determine which kind of diabetes you have. For example, in type 1 diabetes, antibodies attack the pancreas, but people with MODY do not have these antibodies. Your doctor will also look for signs in your blood tests that indicate whether you have insulin resistance. Insulin resistance is not present in non-obese people with MODY; however, it does occur in obese people with MODY.
It may be difficult to tell whether an obese person has type 2 diabetes or MODY. The great majority of obese people with diabetes will have type 2 diabetes. A family history of MODY may be the only clue that this type of diabetes is affecting a particular person.
MODY can also be diagnosed by a genetic test. This type of testing will determine the exact type of MODY, and can be done before a patient has any symptoms. If a mutation in one of the MODY genes is found, then type 1 or type 2 diabetes can be ruled out.