DNA Tests for Heart Disease
Is there a DNA test for heart disease or heart conditions?
Heart disease is the leading cause of death worldwide.
It can run in families and be made worse through lifestyle and behavioral choices such as smoking and a poor diet. The risk of heart disease can also increase based on our age, race and ethnicity.
Genetic factors do play some role in heart disease and other related conditions such as high blood pressure. Family members can pass traits on from one generation to the next, increasing the probability of heart disease in addition a host of external factors.
There are genetic tests for heart disease, and when the results are known it can help doctors understand the risks of developing certain heart-related health conditions.
Based on the results of the test, doctors can also get a better understanding of how a patient will respond to certain kinds of treatment, what medications will work best, and which ones to avoid due to possible adverse side effects.
With a clear picture of genetic risks associated with heart-related conditions in hand, doctors can also begin developing a preventative plan that encompasses diet, exercise and medications so that a patient can work more effectively to achieve optimal health.
What is DNA testing for heart conditions and what can it tell me?
It helps to understand what DNA is and where it comes from so that you can better understand how genetic testing works.
Inside each human cell are chromosomes. Humans have 23 pairs of chromosomes and one chromosome of each pair comes from the mother and one chromosome comes from the father.
Each chromosome is composed of deoxyribonucleic acid, or DNA. This DNA serves as the blueprint for all the information that makes us who we are. The DNA is organized into segments called genes that encode proteins required by the body to grow and function.
Analyzing a person’s DNA can provide insights into a person’s genetic makeup. In turn, this helps a person to better understand their risks and for doctors to make better decisions regarding diet, exercise and medications that can manage or reduce associated heart disease conditions.
Some of the conditions that genetic testing for heart disease can reveal may include:
- Irregularities associated with heart disease and atrial fibrillation such as coronary heart disease, myocardial infarction, simvastatin-induced myopathy and verapamil and QTc interval.
- Peripheral arterial disease that will uncover a predisposition to develop narrow veins, venous thrombosis, and clopidogrel metabolism
- Hypertension, metoprolol metabolism, beta-blockers, verapamil vs atenolol
- Cardiovascular health risks for decreased folate, decreased HDL cholesterol, elevated LDL cholesterol and elevated triglycerides.
- Congenital heart defects such as mosaic trisomy chromosome 9
Who Should Seek DNA Testing for Heart Disease?
Genetic testing for heart disease is widely available and is many times recommended for people who already have a diagnosed heart problem or heart defect.
Testing may also be ordered for people who have fainting or seizure spells, unexplained cardiac arrest, heart failure in people younger than 60 or people who need a pacemaker implant before turning 50.
If a close relative has tested positive for a heart condition, then you are also a candidate to be tested because there is a pattern of inheritance with heart disease. Testing can also be done when a close relative dies unexpectedly, especially if they are under 40.
If cardiac arrest is suspected, preventative testing may be a smart idea.
Daria Ma, a cardiac genetic counselor at the Cedars-Sinai Smidt Heart Institute, advises that genetic testing may be considered for patients who have any of these symptoms:
- Unexplained cardiac arrest or sudden deaths in the family that might have been caused by an undiagnosed heart disease
- Unexplained fainting, or fainting with exercise or emotional stress
- Unexplained seizures, or seizures with normal neurological evaluation
- ICD/pacemaker at under 50 years of age
- Heart failure at less than 60 years of age
- Enlarged heart
- Irregular heartbeat
- Early heart attack, coronary artery disease or stroke (men under 55, women under 65)
- Enlarged aorta or aortic aneurysm in the chest at less than 55 years of age
- Sudden infant death syndrome (SIDS) in the family
- Untreated very high cholesterol level
- Heart defect present since birth
When should you get DNA tested for heart disease?
If you have not already entertained the thought yourself, your doctor or other family members may be the impetus to seek out testing for heart disease.
In broad terms, doctors may order genetic testing if you are pregnant or attempting to get pregnant, if you have a family history of heart disease or other diseases, and if you have symptoms of a disease that sometimes has a genetic component.
Genetic testing during pregnancy is called a carrier screen because it will tell you the risk of passing on heart disease and a number of other diseases to your offspring. You may not have the disease yourself, but you may carry a copy of the contributing gene.
Many types of heart disease run in families and are influenced by a number of genes that interact in complicated ways. Testing is not as effective or useful for some of these conditions.
However, heart disease caused by only one or two genes is different. When this is the case, there is a benefit to the family in identifying what the risk is so that the most effective treatment regimen can be implemented.
Some examples of heart disease that can result from having only one or a few genes include: Brugada syndrome, familial amyloidosis, hypertrophic cardiomyopathy, Marfan syndrome, long QT syndrome and others.
In several cases, a family member will seek genetic testing for heart disease after another family member has passed away from heart disease. Experts suggest that this is less than ideal and that the first person to be tested should be the person who has the most serious manifestation of the disease.
Testing the most affected person identifies genes with the most powerful disease-causing effects. It’s possible that testing other family members may miss these important genes while identifying only those that make less significant contributions.
When comprehensive testing does not find a gene mutation known to cause that person’s disease—which happens frequently—it does not mean there’s no genetic heart disease in the family.
Testing is an individual decision, but each family member who undergoes genetic testing can provide important information that will benefit several family members. Keep in mind that a positive test does not mean that heart disease will develop, it only shows that the family member carries the disease-causing gene.
A positive test also means that it is a good idea to consider follow-up care from a cardiologist before a serious health problem develops.
Where can you get DNA tested for heart disease?
Your best bet is to be tested or get a referral from your doctor.
To date, the only over-the-counter genetic health risk test that has been approved by the FDA is through 23andMe.
However, 23andMe relies on much more simple technology than what you would get in a doctor’s office. It does not test all the variants of a given gene, nor does it test all the genes linked to a given disease.
The reality is, if you have a known risk or have symptoms of heart disease already, you should get a DNA test from your doctor.
For some people, over-the-counter or online tests you can buy with a prescription from your doctor may be an option as well.
Are there over-the-counter DNA tests for heart disease?
An option for some people is to buy an online test or by walking in to a drug store that is available by prescription only.
The best ones can rival tests that your doctor may order, but again, you will need a prescription to secure one. These are less expensive than those administered in your doctor’s office and are an option if you are uninsured or your insurance will not cover genetic testing.
In many cases, insurance companies will not cover genetic testing unless there is a family history that is present.
Online prescription tests can tell you just about as much as tests from your doctor’s office and in some cases, the results of these tests are delivered by an actual doctor or genetic counselor.
Consumer Reports recently published an overview of at-home genetic tests and it may be useful to review the article if this is an option you’re considering.
What is the cost of a DNA test for heart disease?
There are several variables that determine the cost of a DNA test for heart disease.
Costs are primarily determined by the level of the complexity and thoroughness of the test and the company that provides them.
Prescription and online/over-the-counter tests can range from as little as $100 for a simple test that sequences an entire gene, to a more thorough cardiac panel that tests for hundreds of versions of 30 genes linked to a number of heart conditions that costs $250. Prices can continue upward from that price point.
Because these tests require a prescription, they are often covered by insurance. As a result, the co-pay may be little more than the cost of an office visit for some people.
Tests administered by companies that specialize in genetic testing can charge anywhere from $1,000 to as much as $10,000 for an exhaustive assessment of many different types of genes as part of the search for a genetic cause for heart disease.
However, once an initial mutation has been found, family members can be tested for the specific presence of the mutation that has already been identified, resulting in a much lower cost. Since there are potential benefits to many family members, in some cases, families share the cost of testing with their relatives.
How does the process of DNA testing for heart disease work?
DNA testing for heart disease is usually done on the person in a family who has been diagnosed with heart disease.
This allows for the mutation in a person’s DNA to be identified that is responsible for the condition. After the mutation has been identified, other family members can be tested on a much more targeted basis to see if they also have the mutated gene as well which could lead to the identified genetic heart condition.
Most tests done in doctor’s offices start by taking a blood sample from the diagnosed person. The sample is analyzed at a lab before other family members are tested.
Subsequent family members may be able to be tested with a saliva sample instead of a blood test.
To collect a saliva sample (which also is the case for at-home tests), a subject must not eat, drink or smoke for 30 minutes prior to collection. A swab is then run on the inside of the cheek with the same force that is applied as when brushing teeth.
One swab is used per cheek and the brushing motion should take place for about 45 seconds.
How long does a DNA test for heart disease take?
The actual test takes very little time to administer.
But it can take a few weeks to a few months to get results depending on the test that has been ordered, the lab that is being used, and the backlog of tests that need to be reviewed.
What are potential consequences of DNA testing for heart disease that I should be aware of?
There are a number of consequences to consider when testing for heart disease.
One of the most prevalent is the emotional impact the results of a test can have on the person being tested and their family members. Emotional reactions can often produce feelings of anger, guilt, fear, anxiety and sadness, among others.
While there may also be a sense of relief about removing the uncertainties that a test result can produce, others may be disappointed to learn they carry the gene that could be passed along to their children putting them at an increased risk for heart disease.
Because genetic testing for heart disease should ideally involve several family members, those relationships may become strained if there are concerns about getting tested, or if a family member simply does not want to know the status of potential genetic heart disease.
Periodic examinations by a cardiologist may be away around this issue for someone who does not want to pursue genetic testing or who does not want to share results.
Keep in mind that genetic heart disease is an autosomal dominant disease, which means if you get the abnormal gene from only one parent, you can get the disease.
Another consequence may involve cost. Sometimes genetic testing is covered by insurance, and at other times, it is not. Since comprehensive testing can run $10,000 or more, the financial considerations need to be taken into account before proceeding.
Another concern by some people is that genetic test results may be used against them by insurance companies when seeking a policy. The Genetic Information Nondiscrimination Act (GINA) was signed into law in 2008 and provides federal legal protection from the misuse of genetic test results for health insurance and employment.
GINA does not cover the areas of life insurance and long-term care/disability insurance. Some people get around this by getting appropriate insurance before any genetic testing takes place. Some states also have restrictions in addition to those provided by GINA that can offer added protections.
What are the ethical concerns of DNA testing for heart disease?
GINA does afford protections for DNA testing for heart disease, but many people are still concerned about privacy of genetic testing as an overall ethical consideration.
Ethical arguments have been put forth that as a society, people should not be penalized for learning things that could guide their reproductive choices or how they monitor their health, not only for heart conditions, but for all possible genetic conditions. Despite privacy laws, there are still real concerns about becoming unemployable and uninsurable if all parts of a medical condition are revealed.
Employability and health insurance are currently protected against genetic discrimination by law. But life insurance, disability insurance and long-term care insurance are not, and this information may be considered in determining eligibility and rates.
Ethical concerns also arise when there is a difference of opinion between parents and children on the subject of genetic testing.
Discrimination based on genetic testing existed for decades. It continued until the 1970s, when several states in the US required mandatory testing for sickle cell disease among African Americans.
Sickle cell disease is a recessive trait, and carriers of the disease were identified and then notified of the risks of having children with another carrier. African American children were required to undergo mandatory testing before entering school.
Having sickle cell anemia or being a carrier did not prevent a child from entering school but refusal to participate in genetic testing did.
The Health Insurance Portability and Accountability Act (HIPAA), enacted in 1996, prevented insurance companies from denying health care based on predictive testing for individuals transferring from one plan to another.
But the ethical debate regarding genetic testing continues to this day.
Does everyone who gets DNA tested need to have genetic counseling?
In most cases, it is not mandatory, but it is highly advisable.
Genetic counseling helps patients evaluate and understand a family’s risk of inherited medical conditions such as heart disease. Genetic counselors are healthcare professionals who have received specialized training in genetics and counseling.
Before a genetic test takes place, a doctor may require that a patient meets with a genetic counselor who can help decide if testing makes sense and if so, which genetic tests would be the most useful.
After testing, genetic counselors can help interpret results, decide what comes next and give you advice about what and how to communicate with family members and how the results will impact them.
In addition to possible heart disease, people go to genetic counselors for many reasons:
Women or couples who are pregnant or planning to become pregnant may go if there is a personal or family history of a known or suspected condition, if there are abnormal ultrasound findings, or if one or both parents are advanced in age because the chances for chromosome abnormalities such as Down syndrome or single gene disorders such as Achondroplasia increase with parental age.
A visit to a pediatric genetic counselor may be appropriate if a child has a developmental delay, autism, abnormal physical features or multiple birth defects, a family history of a genetic condition or there is a need to establish an underlying genetic cause for problems so that the family will know what to expect in the future, the prognosis of the condition and if there is a chance of having additional children/family members affected with the condition.
Adults may benefit from genetic counseling if there is a personal or family history of an adult-onset genetic condition to help determine the level of risk that they or their children may be diagnosed with/develop an adult-onset condition.
People of all ages may seek genetic counseling to help determine whether or not they have inherited an increased risk for cancer. This is especially important where there is a history of various forms of cancer in a family.
Where can I get genetic counseling?
Genetic counselors work in a variety of settings ranging from hospitals and doctor’s offices to genetic testing labs, research studies, insurance companies and in several other areas of health care.
In many cases, you can choose to meet with a counselor in person or by phone.
Your personal family physician may be able to refer you to a genetic counselor or the National Society of Genetic Counselors has a directory of more than 3,300 genetic counselors and offers a search tool to help you find a genetic counselor near you. To access the tool, go here.
Before you decide on a genetic counselor, check with your insurance company to see if they cover genetic counseling, testing and authorized providers.
What should you do if you tested positive?
The three potential DNA heart disease test outcomes are positive, negative and inconclusive.
Of these, believe it or not, only positive tests are helpful because it means that a lab is reasonably confident that a gene mutation is present that can cause heart disease.
A positive test means that at-risk family members can do predictive genetic testing. When it is determined that family members carry the same gene mutation and are at risk of developing a heart condition, they can be monitored by a cardiologist.
At-risk individuals can also pass along the mutation to their children which means children should also be monitored as well.
A negative result means that a test was not able to find a mutation capable of causing heart disease or any other disease in any of the genes that were evaluated. This result is not considered helpful because it’s still possible that the genetic cause for heart disease could still be present but was not detected by the technology that was used to evaluate the test.
An inconclusive test means that the lab found a change in a gene, but they are uncertain about whether that change is capable of causing a heart condition or if it is simply a harmless DNA variation that occurs in the general population. This is often referred to as a variant of unknown significance, or VUS.
Testing other family members may be required to better understand the significance of a VUS.
Is heart disease preventable?
The good news is that if you have tested positive for genetic heart disease, you can still take steps to minimize becoming a victim.
According to a study by the Center for Disease Control and Prevention (CDC), at least 200,000 deaths each year from cardiovascular disease could be prevented by changing to a more healthy lifestyle.
Heart disease is the leading cause of death in the U.S., taking up to 800,000 lives each year and half of those deaths involve people who are under 65 years old.
The CDC’s report found that about 80% of deaths from coronary artery disease can be attributed to preventable factors like obesity, poor physical activity, heavy drinking, eating unhealthy foods and not keeping your blood pressure and cholesterol under control.
These lifestyle changes could also prevent about 50 percent of stroke deaths as well.
Lifestyle modifications such as eating healthily, exercising regularly, not smoking and better management of blood pressure, cholesterol and diabetes can go great lengths to reducing mortality from heart disease.
Is a DNA test for heart disease right for you?
Ultimately, DNA testing for heart disease is a personal choice.
You must weigh the potential health benefits, emotional considerations, family relationships, financial concerns and other variables that are unique to your situation.
There’s lots of good reasons to support DNA testing for heart disease but do not take the decision lightly. Understand that there is potential value but there are limitations as well.
Also keep in mind that the field of genetic testing will keep on advancing and even if it is not right for you at this point, you could find much more value in it at some point in the future.