Diabetes mellitus, more commonly known as diabetes, refers to unusually elevated levels of glucose (also commonly known as sugar) in the blood.
There are many factors that contribute to the development of diabetes in a person, among them, genetics plays a very important role.
Types
There are two types of diabetes: Type 1 and Type 2. Type 1 is sometimes referred to as juvenile diabetes and mostly occur in young adults and children. Patients diagnosed with type 1 diabetes fail to produce insulin, which is crucial in transforming sugar into energy. Type 1 diabetes is fairly rare and accounts for less than 5% of all diabetes cases. In patients with type 2 diabetes, insulin is not sufficiently produced by the body or the cells fail to take in insulin.
Significance
Although strongly affects the risk of developing diabetes, other environmental factors such as diet and exercise also play an important role in determining whether a person will develop diabetes or not.
Studies with identical twins indicate that the risk of having diabetes for one twin if the other already has diabetes is 50% for type 1 diabetes and 75% for type 2 diabetes. Thus, even a person carries a diabetes gene, it is possible that she or he won't develop diabetes.
Effects
The role of genetic factor in the development of diabetes are stronger in type 1 than type 2.
For type 1 diabetes, there are several environmental facts that may trigger the onset of diabetes. These include an infection, diet, and weather. Breastfeeding in early years may also play important role. People who were breastfed are less likely to develop type 1 diabetes. Studies of the human genome have identified 18 regions in the genome (IDDM1 to IDDM18) that are linked to type 1 diabetes.
For type 2 diabetes, family history is the strongest risk factor for diabetes onset. Type 2 diabetes is also strongly linked to obesity. Researchers have devoted a lot resources to search for the genes of type 2 diabetes. It is now believed that type 2 diabetes involves variations in several genes. Two of these genes, calpain 10 (CAPN10) and hepatocyte nuclear factor 4 alpha (HNF4A), have been identified using whole-genome linkage studies.
Considerations
The influence of genetic factor on diabetes onset is partially reflected through the relationship between race and diabetes incidence. Whites are most likely to develop type 1 diabetes. On the other hand, Mexican Americans, African Americans and Pima Indians are at highest risk for type 2 diabetes.
Expert Insight
In 1962, after studying the epidemic of diabetes on the island of Nuru, Neel proposed that human genes are designed to survive starvation and famine. When food becomes abundant, these genes cause the body to build up fat stores, leading to obesity and increasing risk for diabetes. This hypothesis is often referred to as the theory of "thrifty genes."
Tags: type diabetes, type diabetes, diabetes type diabetes, genetic factor, important role