Frecuencia de los genes de fusión TEL/AML1 y BCR/ABL en pacientes pediátricos con leucemia linfoblástica aguda / Frequency of TEL/AML1 and BCR/ABL fusion genes in children with acute lymphoblastic leukemia

Background: t(12;21) (p12;q22) and t(9;22) (q34;q11) translocations have prognostic significance in acute lymphoblastic leukemia (ALL). The fusion genes TEL/AML1 y BCR/ABL, generated by these translocations, can be easily detected using molecular biology technique. Aim: To study the frequency of TEL/AML1 y BCR/ABL fusion genes in children with ALL. Material and methods: Fifity six children with ALL (age range 1 month- 14 years) were studied, thirty eight from our Temuco Hospital and 18 from the Metropolitan Region. TEL/AML1 y BCR/ABL fusion genes were detected in bone marrow samples using a reverse transcriptase nested polymerase chain reaction (RT-PCR). Results: TEL/AML 1 and BCR/ABL fusion gene transcripts were detected in 13 (23 percent) and 2 (4 percent) children, respectively. No differences in survival were observed between children with positive or negative transcripts for TEL/AML1 fusion gene. However, those positive for BCR/ABL fusion gene, had a significantly lower survival. Conclusions: The frequency of TEL/AML1 and BCR/ABL fusion gene transcripts in these children with ALL is similar to that described by other authors.

Detección de secuencias del gen BCR-ABL mediante RT-PCR en pacientes con leucemia en la IX Región Chile / Detection of BCR-ABL gene sequences using polymerase chain reaction reverse transcriptase in patients with leukemia from the IX Región of Chile

Background: The BCR-ABL fusion gene is the molecular expression of the Philadelphia chromosome. This cytogenetic aberration is the most frequent alteration found in leukemias, which is produced by the translocation t(9;22). Two different fusion proteins are produced depending on the break point (210 kD and 190 kD). The detection of this gene has both diagnostic and prognostic importance, associated with poor prognosis in acute lymphoblastic leukemia (ALL). Aim: To detect BCR-ABL gene sequences in patients with leukemia from the IX Region of Chile. Material and methods: We studied 58 patients: 5 chronic myeloid leukemia (CML), 35 ALL, 15 acute myeloid leukemia (AML) and 3 biphenotypic leukemia. The gene sequences were detected using reverse transcriptase polymerase chain reaction (RT-PCR). Results: BRC-ABL gene sequences were positive in all patients with CML, 2 of 35 ALL (one child and one adult). The remaining patients were negative. We found p210 and p190 co-expression in 2 CML and 1 ALL. Conclusions: Our results are in agreement with other reports. The detection of these and other genetic alterations will allow us to have invaluable diagnostic and prognostic information from our patients with leukemia