MODY (Maturity Onset Diabetes of the Young)

What is MODY

What is Mody?

Maturity Onset Diabetes of the Young (MODY) is an inherited form of diabetes and has a stronger genetic risk factor than other types of diabetes. It is not linked to obesity like type 2 diabetes, although some symptoms are shared. Generally, patients tend to be young and not necessarily overweight.

MODY affects approximately 1% or 2% of people who have diabetes, so it is very rare. In fact, doctors may not be completely aware of it yet, especially since an estimated 90% of people with MODY are mistakenly diagnosed with type 1 or 2 diabetes. It develops before the patient reaches the age of 25 and passes from one family generation to the next. It is directly caused by a change in a single gene. As a result, all children of an affected parent have a 50% chance of inheriting this gene and consequently developing MODY themselves.

By knowing and understanding MODY, people who are affected can be treated in the most appropriate way possible. Furthermore, the best advice possible can be provided about how MODY will progress and what complications can be expected. Families can also be advised about the risks of inheriting the condition.

Types of MODY

There are five known types of MODY:

  • HNF1-Alpha – This is the most common form of MODY, responsible for 70% of all cases. The amount of insulin produced by the pancreas decreases as a patient ages, as MODY develops during adolescence or early twenties. Generally, this type of MODY doesn’t require insulin. Treatment usually consists of small doses of sulphonylureas.

  • Glucokinase – This type of MODY isn’t as common as the other forms. It occurs when the gene that helps the body to recognise blood glucose levels malfunctions. Glucokinase is hard to identify and symptoms develop slowly. Normally it is identified through routine testing, which is important to do so during pregnancy.

People who have inherited this gene are likely to have had birth weight of around 9Ib or more (approx. 4kg). They may have had low blood glucose at or soon after birth, which might have required treatment.

Generally, this type of MODY is treated with a sulphonylureas tablet but may progress to insulin later on.

  • HNF4-Alpha – A less common form of MODY that is usually diagnosed at a later stage.

  • HNF1-Beta – People with this type of MODY can face various health problems. Renal cysts or growths in the kidneys can occur, along with uterine problems and gout. The renal cysts can usually be detected before birth. Furthermore, diabetes tends to develop later, and insulin treatment will be necessary, along with a healthy diet and plenty of physical exercise.

  • PDX1 and IPF1 – Both are the same type of MODY and incredibly rare. To date, there is only one family in the UK that have been affected.


Testing for MODY ensures that you will receive the right treatment and advice for your particular type of diabetes. It will also make you aware of the 50% risk that any future children could have of inheriting the condition. Genetic testing will also will also be offered to your family as well.

You will be tested for MODY by having your blood checked for pancreatic antibodies, as well as another blood or urine test for C-peptide. You will also have your blood taken for genetic testing. Both tests will be completed by your GP surgery or hospital, but the genetic testing will also be sent to a specialist centre for it to be assessed alongside details of your diagnosis and treatment.