Hi Nigel... just a quick skim of the various articles on variant PH translocations came up with the following article. It would seem that you should take the advice of your doctor and not worry about this. complex variant translocation are rare, but in the post TKi era it seems that the response to TKI therapy is just as good as for those with the more mundane PH translocation.
I have copied the link and a snip from the article - which is quite complex research but the message seems to be very positive. So, do not worry- if it continues to bother you do please ask your doctor to explain why this should not be something for you to be concerned about.
Hope this is helpful,
Sandy
Variant Philadelphia translocations: molecular-cytogenetic characterization and prognostic influence on frontline imatinib therapy, a GIMEMA Working Party on CML analysis
http://bloodjournal.hematologylibrary.org/content/117/25/6793.full
Snip........
The availability of double-fusion FISH provides a useful tool with which to investigate the mechanism of the genesis of the variant translocations. In most cases, one chromosome additional to chromosomes 9 and 22 is involved by 2 different mechanisms: 1-step or 2-step. The 1-step mechanism is characterized by a simultaneous translocation of 3 chromosomes in a 3-break event, and the 2-step by a classic t(9;22) translocation, followed by a second translocation between chromosome 9 and the third involved chromosome in a 4-break event.
Other cases may be characterized by additional mechanisms in which multiple simultaneous rearrangements occur in association with insertions and/or deletions. The role of these different mechanisms has been described previously, and no effect on response to IM therapy was shown.8 In the present study, the 1-step mechanism occurred in 18 of 24 (75%) evaluable cases, as shown by FISH signal characterization, whereas we observed a minority of cases with a 2-step mechanism (4 of 24; 16.7%) or with a complex mechanism (2 of 24; 8.3%). In the previous studies, the 1-step mechanism was also more frequent than the 2-step mechanism.4,6,40
Deletions of a sizable portion of the derivative chromosome 9 have been described in 10%-15% of CML patients. These deletions have been found to occur more frequently in patients with variant Ph translocations.4,7,8,11,41
However, a recent study42 asserted that deletions of der(9) do not influence the response or outcome of CML in early CP patients treated with IM.
We did not notice any strong differences in terms of response rate or survival related to the different mechanisms of rearrangement or the number of involved chromosomes; however, we only found 6 cases with 2-step or more complex mechanisms and only two 4-way translocation casIn conclusion, this large series of early CP CML patients treated with IM as a frontline therapy confirms that the clinical characteristics and outcome of patients with variant Ph translocations are similar to those with classic Ph translocations.
Therefore, our data suggest that patients with variant translocations do not constitute a “warning” category in the imatinib era
