Is diabetes hereditary?

Hereditary factors in type 1 diabetes

Type 1 diabetes itself is not directly hereditary, but the genetic predisposition to develop it is.
This means that multiple people in the same family may be diagnosed with type 1 diabetes. Unfortunately, preventing diabetes in families with this genetic tendency is not yet possible.

GoOD to know

Some people have a higher risk of developing type 1 diabetes than others. They have a genetic predisposition to the disease.

Scientists can investigate how high the risk is for developing type 1 diabetes, but at the moment, this has little practical value.

If it becomes possible to predict whether someone will develop type 1 diabetes, scientists can then attempt to prevent the disease.

Some types of diabetes are hereditary. For example, MODY. This type is different from type 1 or type 2 diabetes.

Risk of developing type 1 diabetes

Type 1 diabetes is a complex condition. Multiple factors contribute to its development, and scientists still don’t fully understand the disease.

What is clear, however, is that the risk of developing type 1 diabetes increases if other family members have type 1 diabetes or other autoimmune diseases.

What If Someone in the Family Has Type 1 Diabetes?

In the Netherlands, approximately 1 in 1,000 children has type 1 diabetes—this equals a 0.1% chance.

The risk increases significantly when a close family member has type 1 diabetes:

If the father has type 1 diabetes → 5–6% chance
If the mother has type 1 diabetes → 3–4% chance
If a brother or sister has type 1 diabetes → 5–6% chance
If an identical twin has type 1 diabetes → the chance may be as high as 60% or more

Significant Differences Between Families

Type 1 diabetes itself is not directly hereditary, but some people are more genetically predisposed to develop it. This has to do with specific genes—particularly those involved in the immune system. Multiple genes play a role, and the combination passed down within a family can vary.

In some families, many of these genes are passed from generation to generation, resulting in a higher risk of developing type 1 diabetes, sometimes up to 30%. Other families carry fewer of these genes.
There are also genes that protect the body against type 1 diabetes.
This is why the risk of developing type 1 diabetes can vary greatly between families.

Testing for type 1 diabetes

Scientists have identified a number of genes that are known to increase the risk of developing type 1 diabetes. However, there are more factors than just genes that contribute to someone developing the condition. Therefore, it currently makes little sense to test people for these genes.

Having a genetic predisposition to the condition does not mean that someone will actually develop type 1 diabetes.

Also, at this moment, there is no way to prevent type 1 diabetes. If someone is predisposed to type 1 diabetes, there is no treatment available to stop the condition from developing. This is another reason why genetic testing currently has little value.

Predicting and preventing type 1 diabetes

According to researchers, it is helpful to detect type 1 diabetes early. This ensures that blood sugar levels are less disrupted at the time of diagnosis. In the worst cases, blood sugar levels can become dangerously high, leading to diabetic ketoacidosis.

That’s why scientists are investigating whether they can better predict type 1 diabetes. And whether it makes sense to treat people with a higher risk of the condition earlier.

TESTING FOR ANTIBODIES

This can be done, for example, by examining family members of people with diabetes for antibodies. These are substances produced by the body to fight diseases. In type 1 diabetes, there are antibodies that cause the body to destroy the cells in the pancreas.

Scientists have identified five antibodies that are important in type 1 diabetes. These antibodies reveal that something is happening in the body. The more antibodies present, the greater the chance that someone will develop type 1 diabetes. That’s why researchers are looking into how these antibodies can be measured in the blood. They are also investigating how diabetes can be stopped at its earliest stage.

DIABETER DOES NOT TEST FOR TYPE 1 DIABETES

Currently, scientific research into testing for type 1 diabetes is not advanced enough. It is of limited value to screen family members of people with type 1 diabetes for antibodies or genes. However, we are keeping an eye on the latest developments. Therefore, Diabeter does not rule out the possibility of testing for type 1 diabetes in the future, if research shows that it is useful.

Hereditary diabetes: MODY

Type 1 diabetes is not hereditary. However, there are types of diabetes that are hereditary. These types are caused by a change in a gene. If one of the parents has such a gene, 25% of the children inherit it.

One example is monogenic diabetes, also known as MODY. This stands for Maturity-Onset Diabetes of the Young. This type of diabetes is often diagnosed in young people, but it can also develop later in life.

MODY IS NOT TYPE 1 OR TYPE 2 DIABETES

MODY is often mistaken for type 1 or type 2 diabetes. This is because very few people have this form of diabetes. The diagnosis of MODY can only be confirmed through genetic testing, which can take up to three months.

People are not tested for MODY without reason. At Diabeter, we only conduct this test when there are indications that it is not type 1 or type 2 diabetes.

For example:

if someone is slim and receives a diagnosis of type 2 diabetes
if multiple generations in a family have diabetes, without antibodies present in the body
if a child develops diabetes before the age of 1
if someone requires very little insulin and this does not change over time
if someone has several other conditions alongside diabetes

DIFFERENT TREATMENT FOR MODY

If someone has MODY, a different treatment is often possible compared to type 1 diabetes. For example, some people can take pills and may need little or no insulin.