Volumen: 10 # Number : 1
Publication Date : Enero - Abril Year: 2006
Authors: Alonso, Cristina N.; Gallego, Marta S.; Alfaro, Elizabeth M.;
Rossi, Jorge G.; Felice, María S.
Abstract: Two of the most relevant pediatric ALL prognosticfactors are molecular and cytogenetic aberrations. Theavailability of these studies is limited at the public healthsystem in Argentina. According to the reported inter-national series, the most frequent rearrangements in ALLare TEL-AML1, E2A-PBX1, BCR-ABL and MLL-AF4. TheRT-PCR detection of these rearrangements shows a highsensibility and plays an important role for cryptic trans-locations (as TEL-AML1) that are only detectable bymolecular techniques (PCR or FISH). One hundred andfifty one newly diagnosed ALL patients younger than 15years old were admitted at Garrahan Hospital betweenDec-02 and Sep-05 (M: 84/F: 67). Fifteen of them wereyounger than one year old and 136 were older. The RT-PCRassays for the aforementioned rearrangements were per-formed in 129 of 151 patients (85.4%). RNA from mono-nuclear cells at diagnosis was retrotranscribed usingrandom hexamers, followed by the corresponding PCRusing primers and conditions described in the BIOMED-1protocol. The results were: TEL-AML1: 15 (11.6%); E2A-PBX1: 5 (3.9%); MLL-AF4: 11 (8.5%); BCR-ABL: 2 (1.6%);negative for all of them: 92 (71.3%); positive for otherrearrangements: 4 (3.1%). Molecular analysis confirmed theconventional cytogenetic (CC) diagnosis in 11 patients andadded 22 not detected by CC: 15 TEL-AML1, 1 E2A-PBX1,5 MLL-AF4 and 1 BCR-ABL. Only one t (1;19) observed atCC didn’t show the expected E2A-PBX1 rearrangement. Inconclusion, molecular diagnosis of ALL increases theoverall abnormalities detection and contributes to a bettercharacterization of leukemia. Its incorporation and stan-dardization at public institutions is essential to optimisepatient’s stratification according to risk group with asubsequent better treatment tailoring.
Key words: acute lymphoblastic leukemia, childhood,molecular diagnosis, prognosis.
Pages : 8-12
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