Genetic Testing
How genetic testing helps
Genetic testing is the standard of care for anyone who has a clinical diagnosis of a SADS condition. This means that everyone with a SADS condition should be genetically tested.
If you are diagnosed with a SADS condition, genetic testing can help in 4 ways:
Identify your family mutation to help identify other family members who also have a SADS condition. If your family mutation (variant) is known (someone else in the family has had genetic testing), then you can be tested for your family variant.
If your diagnosis is unclear, genetic testing can help your doctor decide if you have a SADS condition.
Help your doctor guide the treatment for your specific gene mutation.
- Knowing your mutation can affect which medication is chosen and contribute to the decision of whether or not to recommend an ICD.
Participate in clinical trials and research if you wish.
Who should be tested?
All patients receiving a clinical diagnosis of a SADS condition from their physician.
Family members of a person with a known pathogenic or likely pathogenic variant in their family.
Anyone who was tested in a research study and not in a commercial lab or if testing was done more than 10 years ago.
How can I get tested?
Your doctor needs to order this test just like any other medical test. We recommend that you be evaluated by an electrophysiologist or a cardiologist who can then order the test. If you need a physician, we have a SADS Physician Referral Network around the country. The costs of genetic testing are minimal now. Insurance providers generally cover the cost.
Genetic testing results will be returned to your doctor from the genetic testing company. You’ll need to meet with your doctor and get a copy of the report, along with copies of your ECGs.
Interview with a cardiac genetic counselor
If you tested positive with genetic testing
A disease-causing genetic variation (you may also see this called a pathogenic/likely pathogenic variant or a mutation) was identified.
If you (or a family member) tested negative with genetic testing, it could mean any of the following:
You still have a SADS condition but your mutation has not been discovered yet (e.g., this is true for 25% of confirmed LQTS patients whose EKGs, symptoms, and family history are sufficient to make the diagnosis)
You may have a different SADS condition than the specific one you were tested for
You may not have a SADS condition. this needs to be determined very carefully by a knowledgeable physician because there are many people with LQTS and other inherited arrhythmias who may be “concealed” on a resting EKG and whose genetic mutation has not been discovered — so they test negative with genetic testing.
Genetic testing of family members is generally not recommended.
If your test showed Variant(s) of uncertain significance (VUS):
A VUS is a genetic change whose relationship to disease risk is currently unknown or unclear.
The identification of a VUS does not confirm or rule out a genetic diagnosis
A VUS should not be viewed as a positive result.
As more research is conducted and more data becomes available, the classification of a VUS may change to either a benign, likely benign, likely pathogenic, or pathogenic variant.
It is important to note that VUS findings should not be used for treatment decisions.
There are several commercial CLIA-certified labs from which your physician can order your genetic test. As with any healthcare service, it is always a good idea to be a wise consumer and research each company to see which one might be the best choice for you.
What about other family members and testing?
Your doctor will be able to help you determine if other family members should be tested. In general, if your test is positive, your children, siblings, and parents should be tested, too. This means they will have an ECG and then be tested for your specific mutation. This test is less expensive than the initial test.
Based upon the test results of your close family members, others in your family (grandparents, aunts/uncles, nieces/nephews, etc.) may need to get tested, too. You should compile a family health history for your extended family in order to make sure that a physician evaluates everyone who might be at risk for your SADS condition.
Genetic Testing Companies
Ambry Genetics
http://www.ambrygen.com/
Client Services
949-900-5500
Blueprint Genetics
Customer Support
650-452-9340
Gene Dx
http://www.genedx.com/
301-519-2100
Invitae
http://www.invitae.com/
Testing Inquiries
415-374-7782
Prevention Genetics
https://www.preventiongenetics.com/index.php
715-387-048
Also has a DNA banking program