Cytogenetic and molecular genetic studies of number of chronic mylogenous leukemia in Erbil province

Abstract

Chronic myeloid leukemia (CML) is amyeloprolirative disorder characterized by the Philadelphia chromosome originates from the translocation of chromosome 9 and 22 t (9;22) (q34;q11), creating a BCR-ABL fusion gene which results in the constitutive activation BCR-ABL tyrosine kinase. Patients of BCR-ABL fusion gene positive in (CML) are treated by an effective therapy called Imatinib (Gleevec). Point mutations alter the conformation of the ATP binding site that disturbs the binding of therapy to its target which leading to imatinib resistance. Fifty CML patients were collected from Nanakali Hospital in Erbil city which were diagnosed by physicians. The age of the patients from 9 to 80 years, 62% were male and 39% were female, median age of the patients were 38 years. The present study deals with two different aspects; conventional cytogenetic (G-banding) analysis to diagnose the Philadelphia chromosome as a (CML) marker and using Allele Specific Oligonucleotide Polymerase Chain Reaction (ASO-PCR) assay for screening the mutant allele at the three codons 351, 311 and 315 of the BCR-ABL ATP binding domain in Imatinib resistant CML patients. The phenotype of fifteen CML patients were successfully analyzed, thirteen patients were in complete cytogenetic response state (Philadelphia 0%) only two of those patients showed the Philadelphia chromosome. Three point mutations T1052C, T932C and C944T were identified by allele specific oligonucleotide polymerase chain reaction (ASO-PCR). One patient showed T1052C mutation, T932C was detected in three patients and two patients showed the C944T ATP binding domain mutation. In conclusion, conventional cytogenetic and molecular genetic tests are complementary techniques to show the exact types of abnormalities, which allow better evaluation of the genomic aberration involved in CML patients, specifically for kinase domain mutation that plays an important role in different diagnosis, prognosis, therapy treatment and drug resistant management of chronic myeloid leukemia.