Is Type 1 Diabetes Genetic?

Considered an autoimmune disorder, type 1 diabetes is a condition where the body doesn't produce enough or any insulin. The condition has a genetic component: Experts have identified a few gene mutations contributing to type 1 diabetes.

However, genes are only part of the story. Other factors, such as age and conditions during pregnancy, can play a role in increasing type 1 diabetes risk. Read on to learn more about the hereditary nature of type 1 diabetes and other reasons why it might happen.

What Is Type 1 Diabetes?

Type 1 diabetes is an autoimmune disease that interferes with how sugar is available to fuel our bodies. It's a lifelong disease that requires lifelong insulin replacement therapy to manage it.

In type 1 diabetes, the immune system mistakenly destroys the pancreatic beta cells which produce insulin. Insulin is necessary for moving sugar from food out of the blood and into cells, where it is stored for energy. Without insulin, sugar levels rise to levels that can lead to coma and even death—complications of diabetic ketoacidosis.

Is Type 1 Diabetes Genetic?

Scientists have not identified one gene which causes type 1 diabetes. Instead, they've discovered mutations in a tribe of genes called the human leukocyte antigen (HLA) complex. Specific combinations of these mutations—called a haplotype—seem to confer a higher risk of developing type 1 diabetes.

Specifically, these genes help the immune system identify which compounds are natural to the body and which shouldn't be there. Also, the changes in HLA genes only explain about 40% of the genetic risk for type 1 diabetes.

Who Is Most Likely to Inherit Type 1 Diabetes?

The gene variations responsible for type 1 diabetes are passed down in families. Research is ongoing to learn more about this hereditary pattern. For example, some researchers indicated the following statistics for family inheritance:

• Fraternal twins: Approximately 8%
• Identical twins: More than 50%
• Siblings: 6%-10%

Children have a 6%-9% chance of developing type 1 diabetes if they have a father with the condition. The percentage is lower if a mother has type 1 diabetes: Children may have a 1%-4% likelihood of having type 1 diabetes.

Risk Factors

Only a few risk factors are clear when concerning how likely someone will be to develop type 1 diabetes. Other than family history, age is another risk factor. The younger a person is, the higher their risk of having type 1 diabetes.

Other implicated risk factors have included:

• Certain viruses, such as rubella and coxsackievirus, which can cause hand, foot, and mouth disease
• Pregnancy-related factors like complicated delivery, high birth weight for gestational age, and preeclampsia
• Vitamin D deficiency
  

A Quick Review

Type 1 diabetes, a condition that results from your body being unable to use insulin efficiently, has genetic components. Mutations in one set of genes, called HLA genes, are associated with type 1 diabetes cases.

Also, age is considered a type 1 diabetes risk factor other than family history, but there have been other potential factors suggested to increase risk. If you have risk factors or symptoms of type 1 diabetes, see a healthcare provider.