Hereditary FTD and ALS

[Nuch]

Hi there- really struggling to ask this question as I prefer not to know but it will influence my decision to have children. My mom passed last away last August from ALS with FTD. My family history on her side is not great as they werent a close family, but neither of my grandparents had it and my uncle (her older brother) doesn't recall anyone having symptoms that could have been ALS. That being said I have chosen to believe it was sporadic (90% chance). My question is, because she had the FTD as well does that increase the chance of familial (normally 10% of all cases)? I know there is a DNA test to confirm but I am not ready for definitive answers and might not ever want to know that level. From familial cases I understand it is a 50% chance of contracting the disease. Are all my facts and figures correct? Thanks so much for the help!

 

[ghost_writer]

Hello Nuch, I'm sorry about your mother.

You pose an interesting question. I'm from a fALS family. I don't know that FTD increases the chance of inheritance of ALS. I think I remember reading that a genetic marker was found in FTD patients, however not 100% sure.

Your understanding of the figures sounds correct to me. Bear in mind that of the 5- 10% who are fALS, only about 20% of those will have a genetic marker that can be tested. Our family is confirmed by medical history. My mother's grandmother died from what was called at that time "creeping paralysis". My mother was predeceased by two brothers. Mother died in '04. Mother's youngest brother is now in hospice care.

As for testing, it has splintered my family. Not finding a known marker does not mean you are not predisposed, just as with my uncle. If your mother had been tested and a marker found, then you not finding that marker would offer greater reassurance.

Genetic counseling would be required before you could be tested. There are many things to consider. Without a relative with a positive genetic marker and without any other family members with ALS, I expect your counselor would not advise going forward.

Some of our family have choose to adopt. We now have four wonderful children adopted by family members. Others have choose to have children. You may find that genetic counseling will clear your mind and decide to do the same.

If I can answer any questions, feel free to message me on my page. If I can find that study about the marker for FTD, I will post it here.

Roger

 

[ghost_writer]

FYI: The study I remembered reading was made in 2006, by Kevin Talbot and Olaf Ansorge titled: RECENT ADVANCES IN THE GENETICS OF ALS AND FTD: COMMON PATHWAYS IN NEURODEGENERATIVE DISEASE, published in "Human Molecular Genetics, Vol 15, Review Issue No. 3.

The paper suggest the identification of a genetic loci on chromosome 9p and of mutations in specific genes (CHMP2B and DCN1) in famalies with co-segregation of ALS and FTD. I don't know if any labs are testing for these mutations. A question your genetic counselor could answer.

Note this was 6 years ago and there very well may be other markers identified by now.

 

[Nuch]

Hi Roger-
This helps! Knowing you can have the test and still not know for sure (only in the positive) wouldn't make much difference. It also helps to hear what it might have been called in earlier years. Sounds like your family has had a tough go with this awful disease- you will be in my thoughts tonight.
Thanks again- Linda