Cytogenetic Investigation in Chronic Myeloid Leukemia: Study from an Indian Population

Chronic myeloid leukemia (CML) is a malignant neoplasm of hematopoietic cells characterized by abnormalproliferation of myeloid precursors, decreased rates of self destruction and an arrest in cellular differentiation. Thebone marrow and peripheral blood accumulates all forms of mature and immature granulocytes, primarily blastcells. It is the most common type of leukemia seen in India, accounting for 30% of all leukemias. Cytogenetic analysisplays a vital and important role in the diagnosis of CML patients. The present study consists of cytogenetic evaluationof 175 CML cases from the Indian population with ages ranging from 6 – 86 years (mean of 42.8). The study populationincluded 115 males (65.72%) and 60 females (34.28%) with a Male: Female ratio 1.9:1. Out of the175 cases, 164(93.7%) were successfully karyotyped while culture failure was observed for 11 (6.3%). Among the 164 reportedcases, 53 (32.3%) showed a normal karyotype while within the 111 (67.7%) abnormal cases, 96 cases (86.5%) showedthe presence of Philadelphia (Ph’) chromosome with standard translocation t(9;22); Ph’+ve along with secondaryaberrations was detected in 9 (8.1%) cases. Variants of Ph’ chromosome were detected in only one case (0.9%). Ph’-ve CML with other chromosomal aberrations were detected in 5 (4.5%) cases, including +8, del 20q, del 11q andmarker chromosome. Furthermore, we believe that availability of more advanced molecular techniques can be usedas a supportive tool in CML diagnosis even though it cannot fully replace cytogenetics, which remains the backbonefor laboratory investigation of the disease.