Intrachromosomal amplification of chromosome 21 (iAMP21) is defined as the presence of three or more RUNX1 signals on one marker chromosome. It is a distinct cytogenetic subgroup of childhood B-cell precursor ALL. iAMP21 is known to have poor prognosis when precursor treated with standard therapy. Data was screened using keywords ‘intrachromosomal amplification of chromosome 21”, “iAMP21”, “leukemia”,”ALL” using database Pubmed and EuroPMC. A total of 103 records screened and only 9 included in this study. The outcome such as event free survival ranged from 46.9% to 80%. The overall survival of the patients ranged from 64% to 92%. The differences in treatment regimen accounted for this large gap range in event free survival and overall survival.