Philadelphia Chromosome

Okay, this is a stupid question, but if anyone knows, I could use the help. When CML goes into remission, sometimes the Philadelphia chromosome “disappears”. Well, where does it go? By that, I mean, how can a chromosomal mutation that has been clonally replicated into a cell population just disappear? Does this mean the chemotherapy has been so effective that literally all of the cells carrying the mutation, the entire clonal population has been killed? That just seems so unlikely. Or is there some thing else I’m missing? Help. Thanks.

Epidoc, I don’t know either. What happens when the CML returns from remission? Is the chromosome detectable again then? My mother has lymphoma and we have learned (the hard, sad way) that “undetectable” is not the same as “gone.” Her lymphoma was undetectable following chemotherapy for some months… but then it came back.
Where did I hear that people who had great encouraging results on Gleevec were, unfortunately, starting to relapse? I swear I didn’t imagine it but now I can’t remember where I heard it.

I'm so sorry to hear about your mother. I hope she can re-achieve remission.
I do think the Philadelphia chromosome comes back, but I'm not sure. I guess the issue is the difference between undetectable and gone. I hadn't heard about Gleevac users relapsing. My current PBL preceptor is a pharmacologist and has talked about Gleevac, but hasn't mentioned that… or maybe he did, and I missed it, which is very possible.
Good luck to your mother.

I think the Ph+ cell line remains but at such an extremely reduced level that it's not detectable. That is, until the number of cells increases enough to be detected…