Archive for the ‘genetics’ Category

Genetics Unlocks Heart Disease Risk and Treatment

Friday, June 18th, 2010

The standard of care for people with risk factors for heart disease and high cholesterol is statin therapy. Since not everyone reacts well to medication or other treatment modalities, by looking at genetic variants we can better determine who is at risk and what the most effective treatment is.
Previous research has shown that a variant of the KIF6 (719arg variant) gene is associated with up to a 55% increased risk of primary and recurrent coronary heart disease events and that this increased risk is virtually eliminated with statin therapy. To date, the benefit of statin therapy for KIF6 carriers has only been studied with atorvastatin and pravastatin.

An overly simplified process of how disease develops is that small, dense particles of cholesterol get oxidized; the oxidized particles stick to artery walls and inflames them. An artery’s response to inflammation is the formation of plaque that narrows the artery. Plaque builds up and clots form on the plaques further narrowing the arteries. These plaques become unstable and rupture, resulting in complete blockage of arteries in your heart causing a myocardial infarction or blocking arteries in your brain causing a stroke. This process can happen anywhere in your body.

Data suggests that a specific variant of the KIF6 gene may play a role in the inflammatory process that can form unstable plaques which may rupture and block arteries. Once the artery is blocked, the lack of blood flow to the tissues causes death of those tissues and the extent of damage is dependent on the size of the area the artery feeds.

Knowing that you are at increased risk can guide therapy, as statins are not uniformly necessary or effective in all people. Inflammation can also be decreased with diet and supplements and other cardiovascular risk factors could be treated more aggressively.

Genetic testing is now simple and affordable. A simple cheek swab can determine if you have the KIF6 variant gene, as well as other genes that predict risk of cardiovascular disease. Knowing you risk can determine if you should do further testing to look at your other risk factors and extent of arterial blockage as well as to target therapy. Talk to your doctor to determine if this test is recommended for you.

Your Genes Are Not Your Destiny

Wednesday, May 19th, 2010

Contrary to popular belief, your genes don’t necessarily determine your destiny. While many genes are static and determine our sex, eye and skin color, others need to be turned on or off to express a genetic trait. The on or off switch lies on top of the genome or genetic material and is the basis of the study of “epigenetics” (the prefix epi-, means above). The most basic definition of epigenetics is the study of changes in gene activity that do not involve changing the genetic code. These changes get passed down to at least one successive generation. It does not changing the gene, it changes the activity or expression of the gene. The expression of a gene can not only modulate on off but can change enzyme activity, protein production, cellular division and many other biological activities to make more or less of something and do it faster or slower. It’s not always a have or have not or an all or none phenomenon.
So think of a hardware and software analogy. You can have the same computer hardware (genes) but load different software (epigenes) and have different operator (individual lifestyle and environment). While the genes are the same, the outcome can be entirely different. Environmental factors like diet, stress and nutrition can make an imprint on genes that is passed from one generation to the next (epigenetic marks). Lifestyle choices like smoking and eating too much can also change the epigenetic marks atop your DNA. These changes can cause the genes for obesity to express itself, turn a cancer gene on or decrease your longevity. On the contrary, healthy lifestyle choices can quiet the expression of these genes and you can enjoy better health. What is now becoming apparent is that those same bad behaviors can also predispose your kids by passing on these epigenes to them before birth.
Epigenetic changes come from a response to an environmental stressor and can be inherited. The good news is, if you remove the environmental stressors and change your lifestyle, the epigenetic marks will eventually fade, and over time, the DNA code will revert to its original programming. Some genetic variants can be modulated with supplements, nutrition, and limiting toxic exposures and other environmental factors. Seek professional advice to be sure your genes don’t make you blue. Your destiny lies in your lifestyle choices – will they sustain you or drain you?