Is diabetes genetic? The relationship between genes and diabetes is complex. Environmental risks and triggers also play a strong role in developing this condition. Read on to learn more about the genetics of diabetes, and whether a diabetes genetic predisposition means you’ll actually be affected by the disease.
According to the American Diabetes Association, approximately 24 million Americans were affected by diabetes in 2007. What is diabetes, exactly? When we eat, our bodies break down our food into a sugar called glucose. Glucose circulates in the bloodstream until the pancreatic hormone insulin helps it move to the body’s cells, to use as fuel.
When the pancreas either cannot make enough insulin, and/or the cells in the body aren’t able to use insulin properly, diabetes occurs, causing high blood sugar levels.
Types of Diabetes
Diabetes is not a single disease. It is actually a group of diseases that cause high blood sugar. Here are the main types of diabetes:
- Type 1 diabetes: Type 1 diabetes is caused when the body’s immune system attacks the cells in the pancreas that make insulin.
- Type 2 diabetes: This condition develops when the body’s fat and muscle cells aren’t able to use insulin properly and/or the body doesn’t produce enough insulin.
Genetics of Diabetes Type 1
Although influenced by genetics, type 1 diabetes genes usually need to be inherited from both parents in order for a person to develop this condition. This diabetes genetic predisposition is believed to be most common in Caucasian populations, because rates of type 1 diabetes are highest in this ethnic group. Genes that may be associated with risk of type 1 diabetes include:
- HLA-DR3 and HLA-DR4 for Caucasians
- HLA-DR7 for African Americans
- HLA-DR9 for the Japanese.
Scientists are working toward understanding all the environmental triggers for type 1 diabetes in those with a diabetes genetic predisposition. Triggers may include cold weather, early life diet and viruses.
Genes and Diabetes Type 2
Recent studies regarding the genetics of diabetes have revealed 10 new genetic markers for diabetes-related traits, as well as three new variants linked to elevated glucose levels. Compared to type 1 diabetes, there is a much stronger link between genes and diabetes type 2. However, this diabetes genetic predisposition often only occurs in people living a Western lifestyle, including a high-fat, low-fiber diet, lack of exercise and obesity.
It is likely that both genetic and environmental factors need to be present in order for an individual to develop this disease. Here are some facts from the American Diabetes Association about family history and diabetes:
- Almost all Caucasian type 1 diabetics have the HLA-DR3 or HLA-DR4 genes.
- If you were diagnosed with Type 2 diabetes before the age of 50, your child has a one in seven chance of developing the disease. With type 2 diabetics diagnosed after age 50, the risk goes down to one in 13.
- Men with type 1 diabetes have a one in 17 chance of having a type 1 diabetic child.
- Women with type 1 diabetes who have a child before the age of 25 have a 1 in 25 chance of passing on the condition. After age 25, this risk decreases to one in 100.
Adams, A. (2000). What is diabetes? Retrieved March 24, 2010, from http://www.genetichealth.com/DBTS_What_Is_Diabetes.shtml.
American Diabetes Association. (n.d.). Diabetes statistics. Retrieved March 29, 2010, from http://www.diabetes.org/diabetes-basics/diabetes-statistics/.
Mayo Clinic. (2009). Type 2 diabetes. Retrieved March 24, 2010, from http://www.mayoclinic.com/health/type-2-diabetes/DS00585.
Medical News Today. (2010). Genetics of diabetes better understood as consortium discovers novel markers And variants. Retrieved March 24, 2010, from http://www.medicalnewstoday.com/articles/176416.php.