Sisters with ALS

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New member
Sep 14, 2006
Loved one DX
I know this is a unlikely situation but is anyone else aware of siblings having ALS. My wifes sister was diagnosed with ALS in late 2003. In August of 2006 my wife was diagnosed with ALS. My wifes Neurologist is shocked that both sisters had ALS. My wife had blood drawn to check for the sod1 gene but we have not heard back yet. My sister-in-law passed away on December 11th. My wife has already progressed to needing to use a walker and I can just barely understand her. Needless to say this scares the bejabbers out of me. My sister-in-law was 61 when she was diagnosed. My wife is 51. Sorry about rambling but I am still trying to understand what has happened. Are siblings having ALS as unusual as our Dr. thinks.

Hello, welcome to the forum. This is called Familial ALS. Is your Dr. an ALS Dr.? You can do a search and find more info. Just type in Familial ALS. Hope this helps some. My Best to you, Beebe
Hi Steve. Sorry you have to be here asking questions but you have found a good place. In about 10% of the cases of ALS it is familial. It is not unusual and I am quite surprised at your doctor not knowing this fact. A lot of Neurologists do not see that many ALS patients in their career. I have no idea how large Plano Texas is but with his comments I'd suspect he hasn't seen many ALS patients. I'd try for a referral to an ALS Clinic if one is nearby. As you probably know there is not much that can be done but at least the clinic's have the staff to help with day to day living. Good luck and if you need answers or support we will do what we can to help. AL.
Hi Steve,

I'm sorry about your situation. There are 2 possibilities here. Either your wife and sister have sporadic ALS which is true for about 90% of ALS cases or they share a gene that is giving rise to familial ALS (FALS). The SOD-1 gene only accounts for a minority of familial cases so a negative test result will not rule it out. However, when FALS is present in a family they usually know it because it strikes many members in preceding generations. If she doesn't have a good knowledge of her family history however she could have FALS and not realize it.

Alternatively, both she and her sister could have sporadic ALS although the odds of this happening are about 1:250,000 which is still a lot better than the odds of winning a big lottery and people win all the time. The chance of anyone getting sporadic ALS is about 1 in 500 hence the odds of any 2 people, related or not, are 500*500=250,000. I have heard of a few married couples in which both came down with ALS and obviously they did not share a familial gene.

my family has FALS


You should read some of my other posts on this topic. Back in 1973 when my grandfather was diagnosed, he and my grandmother asked the doctor's what the chances of their children being affected by this disease were. They were told there was no chance, that it was an isolated incident. Since, my uncle and my mother have passed from ALS. My grandfather had no knowledge of ALS in his family. Even today, a lot of doctor's out there just don't know the facts.

We have found that our family does in fact carry the SOD-1 gene mutation, which only accounts for 20% of the familial cases. There are several other gene mutations that can cause the other 80% of familial cases.
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