Significance of NOTCH1 mutations detections in T-acute lymphoblastic leukemia patients

BACKGROUND: This study aimed to determine the prevalence and clinical impact of neurogenic locus notch homolog protein 1 (NOTCH1) mutations among patients with T cell acute lymphoblastic leukemia (T-ALL). PATIENT AND METHODS: A cohort of 60 T-ALL cases was included in this study. Sanger sequencing were done for NOTCH1 exon 26, 27, and distal part of exon 34 expanding the sequences encoding transcription activation domain (TAD) and a peptide sequence rich in proline, glutamic acid, serine, threonine (PEST) domains in all studied T ALL patients at diagnosis. RESULTS: NOTCH1 mutations was detected in 40 out of 60 T-ALL patients (66%). Mutations in T-ALL patients are deletions (22 mutations) and point mutation (10 mutations). NOTCH1 mutations was found to have no significant impact on clinical outcome and prognosis in T-ALL including overall survival, progression free survival, relapse and mortality (P > 0.05 for all). CONCLUSION: NOTCH1 mutations were frequently detected in T All patients; however, these mutations did not affect the T ALL patient's outcome. The high prevalence of NOTCH1 mutations at diagnosis could be used for detection of minimal residual disease in T ALL.