What Is Maturity-Onset Diabetes of the Young?

Medically Reviewed by Michael Dansinger, MD on November 06, 2020

Maturity-onset diabetes of the young (MODY) is a rare kind of diabetes that runs in families. Like type 1 and type 2 diabetes, MODY affects the way your body uses and stores sugar from food. But treatment can be different, so it's important to get the right diagnosis.

What Causes MODY?

MODY is brought on by a change, called a mutation, in one of your genes. This is different from type 1 and type 2 diabetes, which are caused by a combination of different genes and other things, such as obesity.

The genetic change that happens because of MODY keeps your pancreas from making enough insulin, a hormone that helps control the level of sugar in your blood.

Who Gets It?

MODY is usually inherited, so your odds of getting it are higher if you have family members with the disease. If you have a parent with MODY, there's a 50% chance that you'll get it. In many cases, the disease reaches across more than one generation. It can affect a grandparent, parent, and child.

The disease usually happens in teens and young adults under 35. But you can get it at any age. Unlike type 2 diabetes, MODY isn't linked with obesity or having high blood pressure. People with MODY are often at a healthy weight.

What Are the Symptoms?

The signs of MODY can depend on which of your genes is affected. In some cases, there may be no symptoms at all. But in general, the disease comes on gradually. You may have high blood sugar for years before you notice one of these warning signs:

What Are the Complications?

Like other types of diabetes, MODY causes high blood sugar levels. If you don't get treatment, over time it can lead to complications like:

How Is It Diagnosed?

Because there can be no symptoms or mild ones, you and your doctor may not realize at first that you have MODY. Your doctor may diagnose you with diabetes when a blood test shows that your blood sugar levels are high. The next step is figure out what kind of diabetes you have.

Your doctor will ask about your family history of diabetes. They may order blood tests that can rule out other types of the disease besides MODY.

Based on these results, your doctor might suggest that you get genetic testing to confirm you have MODY. They'll take a sample of DNA from your saliva or blood and send it to a lab. A technician will look for changes in a gene that cause MODY.

How Is MODY Treated?

There are different types of MODY based on which of your genes has a mutation. Your treatment depends on which kind you have:

MODY 1 and MODY 4. They're usually treated with sulfonylureas, a type of diabetes medication. These drugs cause your pancreas to make more insulin. Some people with MODY 1 and MODY 4 may also need to take insulin.

MODY 2. This disease is usually managed through diet and exercise. You usually don't have to take medicine.

MODY 3. At first, this form of the disease can be treated through diet. Over time, you may need sulfonylureas and then insulin.

MODY 5. You'll need to take insulin to treat it. This rare form of MODY can harm other organs, such as your kidneys. You'll need treatment for complications, such as kidney cysts or kidney failure.

MODY 6. This type tends to appear later in life, around age 40. You'll get treated with insulin.

Show Sources


Diabetes, Metabolic Syndrome, and Obesity: "Clinical Features and Treatment of Maturity Onset Diabetes of the Young (MODY)."
National Institute of Diabetes and Digestive and Kidney Diseases: "Monogenic Diabetes (Neonatal Diabetes Mellitus & MODY)."
Gene Reviews: "Maturity-Onset of Diabetes of the Young."
Harvard Health Publications: "Maturity Onset Diabetes of the Young (MODY)."
University of Chicago Medicine: "MODY."
Diabetes Therapy: "A Case of Maturity Onset Diabetes of the Young (MODY3) in a Family With a Novel HNF1A Gene Mutation in Five Generations."
Archives of Medical Science: "Sulfonylureas and Their Use in Clinical Practice."

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