Who is at risk for diabetes?

According to American Diabetes Association, almost 8% of the US population is suffering from diabetes and around 17.9 million people been diagnosed with the disease. Still, its underlying cause is partly understood. This very much limits both treatment and prevention of the epidemic. Lifestyle factors, such as poor diet and lack of exercise have been known for some time to increase risk of developing the disease, but scientists are becoming more aware of the role played by genetics. Are there any genetic risks related to this condition? These are questions that certainly need to be answered.

A single gene may precipitate a particular disease on its own while other genes cause disease when they act together. Before, finding these gene-gene combinations has been especially hopeless, because the calculations needed to match suspect genes among the 500,000 genes found in the human genome have been almost impossible. To alleviate the problem, some researchers used ELA to compare the genetic makeup of unrelated individuals to sort out disease-related genes. Ensemble Learning Approach (ELA) is software that detects a set of SNPs (single nucleotide polymorphisms) that jointly have a significant effect on a disease in this particular case type 2 diabetes. It is done by drastically narrowing the field of potentially dangerous genes and then applying statistical methods to determine which SNPs act on their own and which act in combination.

The first important clues in an effort to identify of genes associated with diabetes type 2 came from a genome-wide analysis conducted in 2,000 people with type 2 diabetes and 3,000 controls as part of the Welcome Trust Case Control Consortium2. They have identified three such genes. For each of the three genes described on one particular study done, the researchers have found that there are two common versions, one of which is associated with an increased risk of developing type 2 diabetes, and the other with reduced risk. Each high-risk version of the genes increases the risk of type 2 diabetes by about 10-20%. For many people, the risk of being diabetic as they age is influenced by a number of genes as well as their environment. The more ‘high risk’ alleles a person inherits increases the likelihood that they will be diabetic. Two out of the three genes appeared to be involved in the function, development, and regeneration of insulin-producing beta cells, found within the pancreas. This will help answer the questions concerning the extent to which a reduced number of pancreatic beta-cells contribute to the development of diabetes, as opposed to reduced cell function.

A recent international study was able to identify 12 new genetic risk factors. These new gene variants impact the individual’s risk of developing type 2 diabetes. Out of the 12, 11 genes were known to influence insulin production or the effect of insulin. For the very first time, a genetic association of type 2 diabetes with the X chromosome was proven. This is perhaps a clue to the gender-specific variations in diabetes risk: Men have one X and one Y chromosome while women have two X chromosomes. As of the moment, 38 genetic risk factors for type 2 diabetes mellitus are known. Each factor in itself contributes very slightly to the entire risk of acquiring. One important finding of the new study is that some of the gene linked with increased diabetes type 2 risks, are also risk variants for diseases such as coronary heart disease, autoimmune diseases and cancer. This might mean that specific proteins could be relevant for several ailments at the same time.

Diabetes mellitus type 2 is a disorder of glucose homeostasis. Characteristic features of this disorder are increased blood sugar levels and sufficient production of the hormone insulin become lost and develops insulin resistance. The pathogenic mechanisms of this ailment are not yet fully understood. It is however known that combination of genetic susceptibility and lifestyle factors leads to the disease.