Background: Outcome in chronic myeloid leukemia (CML) have improved with tyrosine kinase inhibitor treatment (TKI). Additional chromosomal abnormalities (ACAs) are strongly associated with disease progression but their prognostic impact and influence on treatment response in young adults are yet to be defined. The aim of this study was to analyze the impact of ACAs in Egyptian young adult CML patients on response to treatment.
Materials and methods: The data from the Hematology Department and outpatient clinic of Ain Shams University was collected from young adult CML.    
Results:  At presentation, ACAS were found in 7 patients (8%). During treatment, 4 patients of them had achieved molecular response. While during treatment, ACAS were found in 10 patients. 4 patients of them had achieved molecular response. Also during treatment, chromosome 17 abnormalities were found in 4 patients.Three patients of them didn't achieve molecular response and shifted to tasigna.
Conclusion: ACAS at diagnosis and during treatment has no impact on CML poor risk parameters which denotes that other factors are more significant .Time to molecular response didn't differ between ACAS +ve &-ve patients at diagnosis