MLL-AF4 fusion transcripts in Acute Lymphocytic Leukemia patientsin Children hospital of Tabriz

MLL-AF4 positive Leukemias comprise about 50-70% of acute lymphoid leukemias in children and about 5% of adolescents and adults Despite recent advances in the treatment of hematologic malignancies of children with ALL in particular, but it seems that poor results are obtained from treating this type of malignancy. Perhaps it is due to the lack of enough knowledge about the expression pattern of the fusion gene induced by chromosomal translocations. This study aims to consider several aspects of the common chromosomal disorder, t (4; 11): due to lack of accurate statistical results for this type of translocation in our country, acceptable results are provided; Sprevalence of isoforms of recombinant genes involved in MLL-AF4 are explained. Of 36 patients with ALL between 4 months -11 years of age, peripheral blood sampling was done and total RNA extracted and cDNA was made. Then cDNA was amplified in two steps with the PCR and Nested PCR reactions. After electrophoresis the products were compared and analyzed in comparison with the internal control. The results showed that MLL-AF4 recombinant gene expression in the age between 4 to 12 months range is maximum in the second stage by Nested PCR. Also the highest frequency of fusion isoforms of the gene involved in the same age range is e11-e4 isoform with the frequency of 0.13. It seems that investigation of translocation and chromosomal abnormalities using molecular techniques is one of the most accurate and suitable methods for identifying chromosomal characteristics in patients with acute leukemia, particularly ALL.