Bcr-abl translocation has been found to be the hallmark of chronic myelogenous leukemia. It is present in 90-95% cases of chronic myelogenous leukemia. The present study was performed to check the frequency of Bcr-abl fusion transcripts in Pakistani chronic myelogenous leukemia patients. The frequency of Bcr-abl fusion transcript was determined by using RT-PCR. RNA was isolated from the peripheral blood of 23 CML patients using TRIzol reagent. It was reverse transcribed by using MMLV reverse transcriptase enzyme followed by RT-PCR. RT-PCR was done by using two combinations of primers (BCR-C, CA3) and (B2B, CA3). The PCR product was analysed on 3% Agarose gel. Results: All 23 samples were positive for Bcr-abl translocation. Out of 23 samples 13 (56.5%) were positive for b2a2 type transcript. B3a2 transcript was observed in 6 (26%) out of 23 samples. Other samples gave unusual bands of around 209 bp referring to fusion fragments other than b2a2 or b3a2. None of 23 samples was positive for e1a2 type transcript. In Pakistani population b2a2 type transcript is most frequent in contrast to the studies conducted on other populations. That is perhaps due to the ethnic differences.
CML, Bcr-abl translocation, frequency, RT-PCR.