**3.3 Four-way translocation of Ph chromosome**

Four-way translocation involves four chromosomes including the Ph chromosome. Asif et al. reported a four-way translocation involved in chromosomes 4, 9, 19, and 22. They have reviewed and analyzed 59 cases of CML with four-way translocations reported from the literatures previously. Their analysis showed that 56% of four-way translocation was male, 39% was female, 2% was missing chromosome Y (-Y), and 3% was unidentifiable of sex [33].

Achkar group reported a four-way translocation involving chromosomes 9, 11, 20, and 22 [34]. The same group reported another case with four-way translocations involved in chromosomes 9, 11, 20, and 22. Also, BCR-ABL fusion gene was detected by reverse transcription polymerase chain reaction (RT-PCR). That patient also showed additional chromosome abnormalities involving translocations of chromosomes 7 and 8. Patient showed poor response to imatinib and died for unknown reason [35].
