What is deCODE MI™?
deCODE MI™ is a genetic test for increased risk for myocardial infarction (MI or heart attack), especially MI occurring at an early age, or before the age of 50 for men and 60 for women. It is a reference laboratory test which detects single base changes or SNPs in the CDKN2A/2B gene region on chromosome 9. deCODE genetics has reported, based on studies of thousands of patients, that individuals who are positive for this test have twice the risk of developing early onset MI compared to those without the genetic variants. It is also appears to be a risk factor for MI in general, carrying with it a 1.6 fold risk regardless of age. About 20% of the general population are positive for this test. This has been confirmed in US and other European populations.
Healthy living and targeted treatments of risk contributing conditions such as hypertension, diabetes and elevated blood lipids are the cornerstones of modern prevention of cardiovascular diseases, including coronary artery disease and MI.
Knowing the risk factors for cardiovascular diseases is the prerequisite for taking any preventive actions, including decisions and follow-through on life style changes and aggressiveness of specific treatments.
deCODE MI™ detects previously unrecognized genetic risk of MI that appears to be in addition to well known risk factors such as elevted cholesteral and hypertension. The test may be positive even in patients of families without history of heart attacks. The knowledge of being a carrier of this specific inherited risk is therefore important in the context of one’s overall risk of coronary artery disease and MI and adds the importance of effective preventive regimens, both at the personal level and at the patient-doctor level.
In a 2007 publication in the journal Science (Science, June 8th, 2007; 316(5830):1491-93) deCODE scientists showed that having two copies of the at risk variant on chromosome 9 (defined as a positive test) carries with it about 1.6 fold increase in risk of having an MI. Looking just at those who have had an early MI (before the age of 50 for males and before the age of 60 for females) the risk is 2.0. The results were based on the analysis of 5 independent patient groups and controls from Iceland and the US, totaling 4587 MI cases and 12,767 controls, with all 5 studies giving equivalent results. deCODE’s findings have been further verified by the results of two research groups, one from Canada studying coronary artery disease patients from Ottawa, Texas, and Denmark (Science, June 8th, 2007; 316(5830):1488-91), and the other from Great Britain studying British and German MI and coronary artery disease patients (New England Journal of Medicine, August 2, 2007; 357:443- 453). Both studies verified the significantly increased risk for coronary artery disease and/or MI associating with the same region of the genome on chromosome 9. Thus far these variants have been tested and confirmed in Caucasian populations. Results in other ethnic groups have not been yet been reported.
Patients who are at higher risk of MI based on the deCODE MI test may benefit from more aggressive management of risk factors such as weight, smoking, elevated blood pressure, diabetes and/or high blood lipids. Family history of coronary artery disease and MI is known to be an important risk factor that frequently prompts people to have evaluations for other risk factors or the possible presence of coronary artery disease. Independent of the family history for these diseases knowing the genetic make-up in regard to deCODE’s genetic MI risk markers is relevant since they may be part of the familial risk or an addition to it.
The deCODE MI™ test therefore offers a new factor and added weight to the analysis of an individual’s risk for coronary artery disease and MI which may help the individual and his physician to decide on how aggressive they should be in modification of lifestyle and/or specific drug treatments.