Specific chromosomal abnormalities and gene mutations may serve as diagnostic and prognostic indicators for disease progression and survival. The identification of these anomalies by state-of-the-art molecular (cyto)genetic techniques such as fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), single nucleotide polymorphism (SNP) microarray-based genomic profiling and next-generation sequencing (NGS) can be of paramount help for the clinical management of these patients, including optimal treatment design. The efficacy of novel therapeutics should to be tested according to the presence of these molecular lesions in CLL patients.

Background: Among the known ABL mutations in chronic myeloid leukemia (CML), T315I is of particular importance. The T315I mutation may develop resistant cells that increase disease progression. TWIST-1 expression is impaired in patients with increased drug resistance. Objectives: The current study aimed to measure the expression of TWIST-1 gene in CML patients to investigate its association with T315I mutation. Methods: Peripheral blood samples were taken from 40 CML patients. The expression of TWIST-1 and BCR-ABL1 genes was quantified by real-time polymerase chain reaction (PCR). The gene expression was evaluated by REST software. cDNA was used for amplification refractory mutation system (ARMS)-PCR reaction. Results: Of the 40 patients (age range: 17-75 years) participating in the study, 23 (57.7%) were female, and 17 (42.5%) were male. The expression of TWIST-1 gene was 43 ± 184.09-fold. The T315I mutation was detected in 3 (7.5%) patients. There was a significant correlation between T315I mutation and TWIST-1 gene expression (P = 0.02). Conclusions: According to our results, the TWIST-1 gene expression in patients with T315I mutation was significantly higher than patients without that mutation.