Genetic Testing for ALS
You can get genetic testing to determine whether your ALS has an underlying genetic cause.
The decision whether to get a genetic test or not is a personal one. Some people with ALS want to get tested to better understand why they got the disease, how it might progress and the likelihood their children will develop ALS.
If genetic testing on someone with ALS identified a disease-causing genetic variant, family members can have the option to pursue testing themselves.
The choice for a healthy family member with no symptoms of ALS to have genetic testing is very individual. There are benefits and costs that should be considered. This type of genetic testing is called predictive genetic testing and should be discussed in more detail with a genetic counselor.
Below, we answer your questions about the process of genetic testing for ALS so you can make the right choice for yourself.
What Can a Genetic Test Tell Me?
About two-thirds of individuals with familial ALS and 10% of people with sporadic or singleton ALS (with no known family history) have a known ALS-associated genetic mutation. If you have familial ALS, a genetic test may help you determine what's causing your ALS, as well as the risk of disease in your family members.
Knowing whether your ALS is connected to a specific gene mutation could make you eligible for ongoing clinical drug trials that might be available for those who test positive for one of the specific genes.
In the future, it could also point you or your family members to a gene-targeted therapy (if and when approved by the FDA). Click here to learn more about the genes involved in ALS and why genetic testing is useful.
If a test finds that you have an ALS-associated genetic mutation, your biological family members might also want to get tested, even if they don't have symptoms. A test could help them find out if they have inherited the same ALS-associated genetic mutation.
This type of genetic testing, called predictive genetic testing, often requires individuals who don't yet have symptoms undergo a neurological exam, psychological assessment and genetic counseling before getting tested. Learning your personal genetic status may be helpful in the future.
The decision to have predictive genetic testing is very individual and all potential benefits and costs should be discussed with a genetic counselor. Learn more about genetic counseling here.
Whether your case is familial or sporadic, your doctor might not identify any ALS-associated genetic variants in your genome. For those with familial ALS, this could mean that your ALS was caused by a gene or genes that haven't yet been discovered.
This doesn't mean your ALS isn't hereditary. If doctors can't identify a genetic cause for your ALS, predictive genetic testing isn't recommended for family members.
What Does Genetic Testing Involve?
Genetic testing usually begins with traveling to a doctor’s office or hospital and having a health care professional take a blood or saliva sample. Your sample gets sent to a lab, where technicians isolate your DNA from your sample and test the specific genes that are known to be associated with ALS.
In some cases, your doctor or genetic counselor can order the test for you to take at home. This is offered through many testing laboratories including the ALS Identified program at Invitae (see below for more information).
For an at-home test, you'll receive a testing kit in the mail, and you'll mail back a cheek swab in a prepaid envelope while following the directions of the testing company.
It can take anywhere from a few weeks to a few months to get your results, depending on the type of testing ordered. Your doctor and/or your genetic counselor will talk you through the results, either in person or by telephone.
What Does Genetic Testing Cost?
Health insurance plans will often cover the cost of genetic testing when it's recommended by a physician. Different health insurance providers might have different policies about which tests they will cover, so it's important to speak to your insurance company before getting tested to ask about whether they will cover it.
Some people may choose to pay for a genetic test out-of-pocket when their insurance does not cover the cost of the test. Patient “self-pay” costs are often cheaper than what laboratories charge insurance.
Why Do Some People Decide Not To Pursue Genetic Testing?
Genetic testing is optional, and all benefits and costs should be considered. There can be psychological and emotional reactions when learning information that might impact you and members of your family.
Some people also express concerns about the potential that they'll be discriminated against if genetic testing uncovers a mutation associated with a disease.
Americans are covered by a law called GINA (Genetic Information Nondiscrimination Act) that prohibits health insurers and employers from using one’s genetic information for discrimination.
For example, if someone has a gene mutation putting them at risk for developing cancer in the future, neither their health insurance provider nor their employer can use that information against them. GINA is not comprehensive in coverage and doesn't include life insurance, long-term-care insurance or disability insurance.
Potential insurance discrimination is less of a risk for someone who already has been diagnosed with ALS. If someone with ALS were apply to a life insurance policy, the insurance company could use their medical records and diagnosis of ALS to discriminate against them.
A genetic test result would be unlikely to contribute further to that discrimination in a meaningful way.
Potential insurance discrimination risks are most important to consider if healthy family members with no symptoms of ALS are pursuing predictive genetic testing. The best advice is to make sure one is properly insured prior to having predictive genetic testing.
Free Genetic Testing Through ALS Identified
The ALS Association believes that upon diagnosis, people living with ALS/MND and their families must have the right to access genetic counseling and testing, current education about clinical genetics in ALS/MND and safeguards against genetic discrimination.
The ALS Identified program, sponsored by Biogen and offered through the diagnostic company Invitae, offers genetic testing to people with ALS and their families at no charge.
Invitae’s ALS Panel looks for mutations in more than 20 genes that are associated with ALS, including the C9ORF72 gene. It's available to people with ALS and people with a family history of ALS in the U.S. and Puerto Rico. Only a doctor can order this test for you.
You may take this test at home or in a doctor’s office. If you take it at home, you'll receive a testing kit in the mail and you'll mail back a cheek swab in a prepaid envelope. If you take the test a doctor’s office, you'll supply either a blood, saliva, or cheek swab sample.
About 2-3 weeks later, your doctor will receive your results. Your doctor and/or genetic counselor will have access to the results, who will share them with you and take time to explain the results and their impact on you and your family.
Click here for more information on Invitae’s ALS Identified program and how to participate.
Click here to learn how you can talk to your doctor about genetic testing.
Click here to download a printable summary of this page.
Learn more about genetic testing and counseling in a video from experts through our collaboration with the International Alliance of ALS/MND Associations.