Hi, I'm new, and I hope this is okay. I've been in a debate for a while about this, and would really like it if I could get an answer that I could understand. I'm more or less a layman with some reading, so be gentle with me.

 

It's basically this: Is trisomy technically considered genetic mutation, or is it not?

 

I have been saying it's not, since it's not a change in alleles, the DNA inside the extra chromosome isn't changing. The other side is that I should be more flexible with my definitions and that it's a mutation because it affects the body like a mutation, and I'm just not buying that.

 

Help?

It isn't a mutation, you are correct, trisomy can happen in the case of any chromosome number however the embryo in most eventualities isn't viable.

 

The remaining DNA isn't mutated the issues are caused by there being much of it.

 

Mutation is defined by a changing in the bases (ACTG) within the DNA, this can be a single base change, large segment movement or deletion.

That's what I always thought. Though I don't have sources to back it up. I did some googling and though the results implied that, I couldn't find an explicit statement.