SIR Medicine Investigation Abstract
ASSOCIATION OF ENDOTHELIAL NITRIC OXIDE SYNTHASE (ENOS) GENE POLYMORPHISMS WITH ABDOMINAL AORTIC ANEURYSMS
Presenters:
Stephanie H. Lee, Illinois Mathematics and Science Academy
Isabella T. Rossi, Illinois Mathematics and Science Academy
Advisors:
Dr. William Pearce, Northwestern Memorial Hospital
Mrs. Vera Shively, Northwestern Memorial Hospital
Abstract:
Abdominal aortic aneurysms (AAA) are characterized by a localized weakening and dilation of the aortic wall and the presence of atherosclerosis. If untreated, they will enlarge and may rupture. The cause is unknown and is multi-factorial. Endothelial cells line arteries and produce eNOS, an enzyme that forms nitric oxide (NO). NO is responsible for maintaining arteries in a relaxed state, preventing blood clotting that impairs blood flow. Several polymorphisms have been identified in the eNOS gene. Polymorphisms are changes in genetic sequences, which may be linked to a disease, that are found in the population. In the case of eNOS, certain polymorphisms have been associated with cardiovascular diseases.
We investigated the T-786C and 4a/4b polymorphisms of the eNOS gene to see whether they are associated with AAA. T-786°C is located in the promoter of the gene. The rare -786°C allele causes a reduction in the eNOS enzyme activity, resulting in less NO production. The 4a/4b polymorphism is located in intron 4, and the rare a allele has been associated with heart disease and cardiac arrest.
Using DNA isolated from patients with AAA plus controls, Polymerase Chain Reaction (PCR), restriction endonuclease digestion, and gel electrophoresis are used to genotype the DNA samples. We anticipate the -786°C allele of T-786°C and the a-allele of 4a/4b to be more prevalent in AAA patients.