Genetic Testing
How genetic testing helps
If you are diagnosed with a SADS condition (inherited arrhythmia condition) and no one in your family has had genetic testing, genetic testing can help in two ways:
Identify your family mutation to help identify if other family members also have a SADS condition
Help your doctor guide the treatment for your specific gene mutation
Prepare for clinical trials and research
Knowing your mutation can affect which medication is chosen and contribute to the decision of whether or not to recommend an ICD.
If your diagnosis is unclear and your family mutation (variant) is known, genetic testing can help clarify whether or not you have an inherited arrhythmia. Parents, siblings, and children (or future children) can also be tested for the “family mutation” to see if they need to be treated.
If your diagnosis is unclear and no one in your family has had genetic testing, genetic testing can be done on a person in your family that has already been diagnosed, or the person who has the strongest likelihood of having a SADS condition. If they test positive, then you can be tested for their mutation – because it is considered your “family mutation (variant)”.
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.
There are several commercial CLIA-certified labs from which your physician can order your genetic test. The cost of genetic testing today is around $250 and is many times covered by insurance. 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.
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 or more than 10 years ago.
*Confirming the presence or absence of a pathogenic or likely pathogenic variant is a less expensive or free, limited test done rather than extensive clinical testing (ECG, EP study)
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, or even free in some cases. Insurance providers generally cover the cost, but will vary.
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.
If the test results come back positive, it is very important to discuss having other family members tested.
What are the steps to get tested?
Step 1
Meet with a cardiac genetic counselor or your doctor to discuss the genetic testing process and obtain a sample.The test needs to be ordered by your physician. The sample can be a blood sample or a saliva sample or a cheek swab.
Step 2
About 4-6 weeks after sending your sample, your doctor and team will receive the results.
Step 3
You should then meet with your cardiac genetic counselor or doctor to discuss these results and get a copy of the report. (You should always ask to receive copies of your ECGs, test results, etc.)
Step 4
If your test results come back positive, it is very important to discuss having other family members tested.
Learn more from a cardiac genetic counselor
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
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..