In the current study (26 cases), the frequencies of the most frequent genetic rearrangements TEL-AML1, MLL/AF4, BCR-ABL (major and minor) in ALL in children from Mexico City were determined.     ///    "For the ALL, the frequency of MLL/AF4 was 65.4%, for TEL-AML1 and that of BCR/ABL was 3.8%. "