Genetic and cytogenetic markers in leukemia: unraveling the pathways of the disease

Abstract

Chronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm characterized by the clonal expansion of abnormal leukocytes, which compromises normal hematopoiesis. A key milestone in its understanding was the discovery of the Philadelphia chromosome (Ph), resulting from the reciprocal translocation t(9;22)(q34;q11), which generates the BCR-ABL1 fusion gene. This gene encodes a constitutively active tyrosine kinase protein, responsible for promoting excessive cell proliferation, inhibiting apoptosis, and inducing genomic instability. This study aimed to conduct a narrative review on the contribution of molecular biology and cytogenetic techniques in the diagnosis and monitoring of CML. The search was carried out in the SciELO, Google Scholar, PubMed, LILACS, and BIREME databases, using the descriptors “chronic myeloid leukemia,” “molecular biology,” “cytogenetics,” and “diagnosis.” Articles published between 2019 and 2024, in Portuguese, English, and Spanish, were included. The analysis of 10 articles showed that the diagnosis of CML combines hematological tests with specific molecular techniques, such as fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR), which allow the detection of the Ph chromosome and the BCR-ABL1 transcript. These methodologies not only confirm diagnosis and staging but also provide essential information for prognosis and therapeutic monitoring. It is concluded that the integration of cytogenetic and molecular approaches is indispensable for the clinical management of CML, making them a strategic tool of precision in patient follow-up and in guiding more effective therapies.