en Adults Hematology & Oncology Adults Hematology & Oncology پژوهشي Original Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:2;">The reciprocal translocation between chromosomes 9 and 22, known as the Philadelphia chromosome, results in the formation of the BCR/ABL fusion gene. This genetic aberration leads to dysregulation of intracellular kinase activity. The detection of the Philadelphia chromosome is a critical component of the diagnostic evaluation of myeloproliferative neoplasms and acute lymphoid leukemia. In treatments involving tyrosine kinase inhibitors, at least 70 genetic variants have been documented as factors that induce resistance to drugs. This includes the T315I mutation, which has been identified as the most prevalent in multiple countries and is of significant clinical significance. This mutation is detected in patients who have experienced therapeutic failure, thereby significantly restricting the available treatment options. In Colombia, the prevalence of this mutation and the dynamics of its appearance are not yet fully understood. Furthermore, there is a paucity of information regarding the management and prognosis of patients who express the mutation. In this study, the genomic DNA of 26 patients with Philadelphia chromosome was analyzed using the real-time molecular technique PCR. The objective was to identify the T315I genetic variant, which was positive in two of the patients diagnosed with CML. We present a case of a 39-year-old female patient diagnosed with Ph+ CML who exhibited resistance to treatment and detection of this mutation.</span></span></span></div> Chronic myeloproliferative neoplasm, Philadelphia chromosome, BCR/ABL. 5 13 http://ijbc.ir/browse.php?a_code=A-10-2103-1&slc_lang=en&sid=1 Carolina Jaramillo Jaramillo 100319475328460012497 100319475328460012497 No School of Bacteriology, Colegio Mayor de Antioquia, Colombia. Juliana Pérez Mejía 100319475328460012498 100319475328460012498 No Health Sciences, Colegio Mayor de Antioquia, Colombia. Sara María Rave Zapata 100319475328460012499 100319475328460012499 No Antioquia, Colegio Mayor de Antioquia, Colombia. Maria Isabel Villa Palacio 100319475328460012500 100319475328460012500 No Faculty of Health Sciences, Colegio Mayor de Antioquia, Colombia. Diana Carolina Velasco Cardona dcvelasco@est.colmayor.edu.co 100319475328460012501 100319475328460012501 Yes Health Sciences, Colegio Mayor de Antioquia, Colombia.