Genetic risk of type 2 diabetes
Common diseases such as type 2 diabetes (T2D) occur at the interface of genes and the environment, as both inherited as well as lifestyle and other health risk factors play important roles in the disease process. As a result, it is important to understand what carrying an inherited risk variant for a common disease means, and how that information can help to keep a predisposition to a given condition from ever developing into a disease.
In the most basic terms, carrying a genetic risk variant for a common disease does not mean that one will develop the disease; and not having a certain risk variant does not eliminate the possibility of developing the disease. Rather, for the common diseases, genetic risk variants impact the likelihood that one may develop the disease. Understanding this inherited risk is empowering information.* This is particularly true in a disease like T2D, in which specific lifestyle and health factors are known to play such an important part. Despite inherited risk, it is possible to take preventive action through lifestyle modification or by taking certain medications to reduce or minimize the likelihood of an individual ever developing a disease. This is similar to the approach that is taken to address other risk factors for common diseases, such as high cholesterol, which is commonly treated using statin drugs to reduce the risk of heart disease.
deCODE T2 is the first test ever offered that detects a common genetic variant associated with increased risk of T2D. deCODE T2 detects a version of a single SNP (single nucleotide polymorphism) a one letter variation in the sequence of the genome in a gene called TCF7L2 that deCODE has linked to increased risk of T2D. In deCODEs findings, published in 2006 and which have since been validated in studies by independent researchers in tens of thousands of people from populations around the globe, between 8-11% of the general population have been shown to carry two copies of the risk variant, where as two copies are approximately two times more frequent among type 2 diabetics. In other words, having two copies of the risk variant – a positive result for the deCODE T2 test has been shown to correspond to an approximate doubling of the likelihood of developing T2D. (Remember that we all have two copies of each chromosome in every cell in our bodies. We inherit one copy from our mother, and one from our father.) Analysis of data from a U.S. government supported clinical trial involving prediabetics has also shown that prediabetics with two copies of the risk variant are at an increased risk of progressing to type 2 diabetes within the next four years but that this risk may be significantly reduced through weight loss and treatment with certain insulin response-boosting medications.
An individual with two copies of the risk variant will receive a positive result for deCODE T2, and those with only one or no copy of the risk variant will receive a negative result for the test.
deCODE T2 is performed in deCODEs CLIA-registered laboratory. The test can only be ordered by qualified physicians and medical practitioners. If you are a doctor or medical professional, we invite you to learn more and how to order the test for your patients by clicking on the link at left.
Read more: Empowering prevention* of type 2 diabetes >>