Is Diabetes Genetic?

Summary

Diabetes is a group of diseases that result in too much sugar in the blood. The condition can have serious health complications and requires lifelong treatment and lifestyle management.

A person’s risk of having pre-diabetes and developing diabetes is influenced by their family health history. For instance, if your parents or siblings have diabetes, you are more likely to get the condition yourself. If this is the case, it is important to talk to a healthcare provider and develop a plan for preventing or delaying onset of the condition.

Let’s dive in to better understand how genetics and family health are related to diabetes, and what can be done to prevent or delay a diagnosis.

Family Health, Genetics & Diabetes

Genetics is the study of genes and heredity. Genes are pieces of your DNA that instruct your body to make specific proteins. Although most of us share the same exact genes, slight differences in the gene’s DNA sequences account for the differences in how we look, how we act, and how likely we are to develop certain medical conditions [0].

Every person has two copies of each gene - one from each parent. When we say that something is hereditary, we mean that it can be passed from parents to their children. Such is the case for eye color and the increased risk of getting a certain disease [1]. For example, conditions like cystic fibrosis, muscular dystrophy, and some cancers are considered hereditary.

Our genes carry information that can affect our health. Because families share similar genetics, it is important to know your family health history. Combined with shared environments and lifestyles, family history gives healthcare providers clues into an individuals risk of developing certain conditions.

So, is diabetes genetic?

Well, yes and no.

Diabetes does run in families, and genetics can influence the risk of developing the disease. However, genes are not the only factor in whether or not someone will develop diabetes. Typically, an individual both inherits a predisposition to the disease and it is triggered by something in the environment [2].

We find evidence for the combination of genetic and environmental factors through twin studies. A set of twins share the same genes, however when one twin develops type 1 diabetes, the other gets the disease only half of the time. The same is true for type 2 diabetes, however the association with genetics is stronger in this case [3].

Hereditary Inheritance of Type 1 Diabetes

Type 1 diabetes is a chronic condition in which the pancreas produces little or no insulin. As a result, glucose is unable to get into cells and blood sugar rises above normal.

Generally for type 1 diabetes, individuals need to inherit risk factors from both parents. The likelihood of a child developing type 1 diabetes is 1 in 17 for a man with type 1 diabetes and 1 in 25 for a woman under the age of 25 with type 1 diabetes. If both partners have type 1 diabetes, the child’s risk is between 10% - 25% [2].

Even with family history of diabetes, those who are risk do not always develop the condition. This shows that environmental factors are at play, however it is difficult to identify exactly what these factors are. Researchers believe that triggers might include cold weather, viruses, and eating solid at an earlier age [2].

Research is currently being done to understand the genetic markers that might point to a higher risk of type 1 diabetes. Many white people with type 1 have genes called HLA-DR3 or HLA-DR4 [2]. Being white and sharing these genes with your child will increase their chance of developing diabetes. Genes in other racial groups are less known, and more research is being done to identify markers that can help researchers and doctors better predict a person’s risk.

Hereditary Inheritance of Type 2 Diabetes

Type 2 diabetes affects the way that the body processes glucose, either through reduced insulin production or by resisting inulin. Since the body is unable to process glucose, individuals with type 2 diabetes have higher blood sugar.

As we talk about in this article, certain risk factors increase the likelihood of developing type 2 diabetes; risk is increased in individuals who are overweight or obese and those from certain ethnic and racial backgrounds. Someone is also more likely to get the condition if they previously had gestational diabetes (diabetes when they were pregnant). You can see our post about gestational diabetes to learn more.

Compared to type 1, genetics play a stronger role in the development of type 2 diabetes. Twin studies show that if one twin has type 2 diabetes, the other twin has a 75% change of developing it [4]. Researchers have found more than 150 DNA variations that are associated with the development of the disease. These variation act subtly on various aspects of the body’s functions. Coupled with environmental factors (diet, lifestyle, etc.), certain genetic variations influence an individual’s overall risk [5].

There is not a genetic smoking gun, and type 2 diabetes does not have a clear pattern of inheritance [5]. There is also not only one thing we can point to that affects the development of the condition. There is still a lot of research needed to understand the ways in which gene variations contribute to disease risk.

How To Know

If you have a family history of diabetes, your healthcare provider might screen you earlier than normal for diabetes. Screening could include genetic testing to look for specific markers that are more common in people with the conditions, or could be screening tests that help identify risk based on environmental and behavioral factors. There are a few online tools that can also help you identify your risk of having pre-diabetes, such as the risk assessment test from doihaveprediabetes.org.

For children who have siblings with type 1 diabetes, an antibody test can be done to measure antibodies to insulin or islet cells in the pancreas.

What to Do

Even if your genes put you at risk, you can still prevent the development of pre-diabetes and type 1 diabetes by eating healthier, engaging in physical activity, not smoking, and maintaining a healthy weight. These positive lifestyle behaviors can even reverse the impact of pre-diabetes on your body [6].

The use of personalized medicine can also help healthcare providers address a specific needs. Personalized healthcare takes into account an individual’s genetic profile - in addition to their family history - in order to guide the prevention, diagnosis, and treatment of disease. Tools like Utu focus on providing personalized care and treatment recommendations based on how your body reacts to interventions, medications, and behavior changes. We’re working on developing powerful algorithms that can learn from you and people like you so that you can take proactive control over preventing diabetes or reducing the impact of the disease [7].