How does genetic testing work?

If you decide to get genetic testing, your genetic counselor will be with you every step of the way to guide you through the process. Here’s how it works.

Step 1: If you decide you want to move forward with testing, your counselor will order the most appropriate tests for you. If you have access to your family member’s genetic testing results, your counselor will use this information to decide what tests to order for you.

Step 2: You’ll provide a DNA sample. This can be a sample of your blood or saliva.

To give a blood sample, you’ll go to a hospital or another testing location to get your blood drawn. To give a saliva sample, you’ll need to spit in a tube or swab the inside of your cheek. Your counselor may give you a test kit to collect your saliva sample at home, or you may need to go to a testing location.

Your DNA is the genetic code that tells your cells how to function. Think of DNA like a set of instructions. If some of the “words” in the instructions are spelled differently, it may cause health conditions like ALS.

Step 3: Your counselor will send your sample to a lab. The genetic testing lab will “read” your DNA to see if you have genetic differences linked to ALS or related conditions. This step usually takes about 4 to 6 weeks.

Step 4: Your counselor will explain your testing results and offer guidance to help you plan for the future. You decide when (and if) you want to find out your results — there’s no rush or timeline to follow.

Keep in mind: Genetic test results may be posted on your patient portal and shared with your doctors. If you’re not ready or not sure that you want to find out your results, ask your genetic counselor for advice.

You can ask your counselor for a copy of your results. It’s a good idea to save your results in a safe place so you or your loved ones can look back at them later.