Question about genetic test results

[Marieb425]

Hi everyone,

We received these results back when we were in processing mode and we didn’t really look at it much. But I curiously looked at it again and I found it interesting that he had some “repeats” in the C9orf72 gene (even though it still says he’s in the normal range). Any thoughts on what this means? Does this mean that this could have contributed to him getting ALS maybe with other factors?

 

[Nikki J]

I don’t see the number of repeats but anything 20 or less is normal so wouldn’t be contributory. As it says repeats in the normal range are not concerning Everyone has at least a couple in each allelle ( you inherit a strand from each parent so if you are given numbers there would be two). I think the trend now though is not to give numbers. Even people who have a c9 mutation don’t get their normal strand number anymore. Their reports seem to say greater than x ( wherever their cutoff is ) and that it is pathogenic.

when I was tested ( 10 years ago) and the test was fairly new my report said greater than 44 and 2. The greater than 44 was abnormal. The two from my other side was normal. Most people with c9 mutations have hundreds or thousands of repeats but testing for exact numbers isn’t done clinically because as far as we know it doesn’t matter after you reach the pathogenic stage ( over 30) 20-30 is borderline

 

[affected]

It does note that the repeats are within the normal range and not associated with disease which is great news.