Genes Can Cause Type 1 Diabetes

Type 1 Diabetes is a chronic illness, recognized as being genetically linked; almost 20 genes have been identified to be involved in the development of this disease. However, Type 1 Diabetes does not appear to be inherited on a dominant or recessive basis, due to the fact that so many genes can contribute towards the risk of developing this disease. Two genes in particular, appear to play a significant role in this risk; the insulin gene and the HLA region genes.

The Human Leukocyte Antigen (HLA) region is composed of many genes involved with the production of proteins necessary to distinguish self cells from infectious agents, hence contributing to the functionality of the immune system. Unfortunately, when this system fails to function correctly, the immune cells attack the pancreatic cells (self cells). This process is known as an autoimmune reaction and results in limited or no production of insulin within the body. Recent evidence has indicated that gene X; an additional gene located on chromosome 6, within the HLA, can increase a person’s risk of experiencing this particular autoimmune reaction by 80%. Another two genes, within this region which contribute further to the risk of inheriting Type 1 Diabetes are known as the DR and the DQ genes. The DR3 and DR4 forms of the DR gene are present in a large percentage of people with Type 1 Diabetes; the severity of this disease is determined by which DR genes are inherited. DQ also contributes to the development of this chronic disease; some alleles of this particular gene can increase the risk of developing Type 1 Diabetes, while other DQ alleles appear to protect the individual from the disease. DQ and DR genes tend to be inherited together which contributes further to the prevention or development the disease.

Another gene which plays a critical role in the development of Type 1 Diabetes, is found in the DNA region which encodes for the production of insulin; the insulin gene. Variations in the DNA region located close to this particular gene can infact contribute to the susceptibility of developing diabetes. Also, depending upon the length of the repeated regions of DNA in this particular location; known as the Variable Number of Tandem Repeats (VNTR), this can also increase or decrease the risk of getting Type 1 Diabetes. However, like any other phenotypic trait, the development of Type 1 Diabetes is determined by both the environment and hereditary factors and research is still being undertaken to discover what exactly causes this life-long disease to arise.

By Shannon Logan 41760307

Information obtained from:

Genetic Health – Diabetes: Genes can Cause Type 1 Diabetes
By Amy Adams, MS
Reviewed By Jeremy Walston, MD and Kristi Silver, MD
Last updated September 14, 2000
<http://www.gentichealth.com/dbts_genetics_of_type_1_diabetes.shtml>
Cited: 17/5/08

VIVAT Online - Type 1 diabetes genetic risk higher than previous estimates
University of Colorado
September, 2006
<http://www.uchsc.edu/vivat/2006/September2006/diabetes_risk.html>
Cited: 24/5/08

Picture: http://www.citisletstudy.org/images/edt.jpg

Relevant Links
http://www.genetichealth.com/DBTS_What_Is_Type_1_Diabetes.shtml http://www.genetichealth.com/DBTS_Other_Diseases_in_Type_1_Diabetes.shtml