Genetics and Diabetes - Understanding the Connection

By: Dan Weiman for Diabetes1

 

Diabetes is a chronic disease we still know relatively little about. While the treatments and side effects of diabetes are understood, the science is still unclear as to why certain people are more apt to develop diabetes and what steps can be taken to prevent its onset. Making the matter even more complex, there appears to be differing genetic origins between type 1 and type 2 diabetes. One fact does remain constant: A high genetic probability for inheriting the disease does not guarantee that diabetes will develop in that person.

 

Still, understanding the genetic parts of the diabetes equation may help to more effectively treat and one day even cure diabetes. It is important to first separate type 1 and type 2 diabetes. Type 1 diabetes develops earlier, and appears to have somewhat of a genetic basis. Type 1 diabetes is more common in Caucasians, and is more likely to manifest in a child if both parents carry genes for diabetes. In fact, the likelihood of a child of diabetic parents developing diabetes is thought to be between 10 and 25 percent. However, while genes may increase the likelihood of a child having diabetes, it is generally thought that there must be an environmental trigger for the disease. While there is not a proven cause, some data suggests that cold weather along with some early dietary considerations such as not breast feeding, may increase the likelihood that type 1 diabetes will be triggered in that person.

 

Type 2 diabetes seems to express itself through genes differently than type 1 diabetes does. Type 2 diabetes has a stronger genetic basis than type 1. For example, if one sibling has type 2, then the other’s chance of having the disease as well is between 60 and 75 percent. Also, if a person’s parents both have type 2, then that person has a 50 percent chance of having the disease. Furthermore, the disease is prevalent amongst certain ethnic groups including African-Americans, Latinos, and American Indians. However, much like type 1 diabetes, type 2 diabetes also has triggers. A common trigger for type 2 diabetes is obesity.

 

While environmental factors have complicated our understanding of the genetic inheritance of diabetes, the genes themselves also complicate matters. While our understanding is limited, it now appears that the expression of diabetes genetically is a polygenetic process. In other words, there is no single gene for diabetes, but rather a number of genes acting together to express the disease. The complex nature of genes and the human genome ensure that gaining a full understanding of the genetic nature of the disease will prove long and difficult.