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Ask the Doc: Q & A with Edward Kasarskis, MD, PhD Edward Kasarskis, M.D., Ph.D. is Director of the multidisciplinary ALS Center at the University of Kentucky Neuroscience Center in Lexington, Kentucky, professor in the Department of Neurology at the University of Kentucky, and Chief of Neurology at the VA Medical Center in Lexington KY.
Q: My father died of ALS 28 years ago, and subsequently, my first cousin also died of the disease. Both were diagnosed in their late 40’s, and I’m 47 but not having symptoms. Genetic testing was not done prior to their deaths. Is there any way to know if we’re dealing with a case of familial ALS? A: The short answer to your question is yes, there are ways to help you know what you’re dealing with. But there’s a lot you should know before deciding if genetic testing is right for you and for your family. First, a little background. ALS is hereditary in just a small percentage of families. Only about 10% of people with ALS have a close family member with the disease. In such cases, it’s called “familial ALS” or “FALS” for short. To date, research from around the world has identified at least 8 different genes associated with FALS and the list is expanding. The first gene identified was SOD1, but it is now believed that mutations in the C9orf72 gene might be the most common. Others include FUS and TARDP. You can get many more details about genetics and heredity in ALS by clicking here. Don't let some of the technical and scientific detail intimidate you. Commercial testing is available for most of these genes (but it’s very expensive). You should know that any single family with FALS has only one mutation in one of the genes, so if you are like most people, you probably will need some professional advice (more about this later). In a situation such as yours, the best first step is to talk with a neurologist or genetic counselor about your family history. He or she will explore the details of your family history with you and provide you a better understanding of whether you’re actually dealing with familial ALS. But let’s just say the genetic counselor or neurologist suggests you get genetic testing. There’s still much more to consider in order to make a truly informed decision. You should first take a step back and ask yourself why you’re interested in getting a genetic test in the first place. Perhaps you’re wondering if you should have children? Or, if your children should have children? Or maybe you find you’re worrying about the disease and whether or not you are going to get it, and that’s causing you constant anxiety? Or perhaps others in the family are wondering? A genetic counselor will help you evaluate your concerns and decided whether genetic testing will likely be helpful to you. Sending blood off to test for these genes is easy; answering these questions may be very hard. The fact that you asked the question in the first place indicates to me that there are some issues that need further exploration with your neurologist and/or genetic counselor. In the end, you may chose not to have any genetic testing. Even if you get a genetic test and find out you have one of the ALS genes, you may still end up with more questions than answers because:
From my point of view, unless someone has several generations involved -- a grandparent, a parent, an uncle or an aunt, a brother or a sister -- genetic testing may not offer the information you’re looking for. Good luck on your quest. For more detailed information on the genetics of FALS, see the Q & A on The ALS Association website. If you would like to submit questions for a future Q & A, please send your questions to theexchange@alsa-national.org. Please understand that we won’t be able to address all questions and we won’t be able to respond to individuals personally. |
