e18516 Background: T-lineage acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease that arises in a multistep fashion through acquisition of several genetic aberrations. Absence of biallelic deletion of TCR-γ (ABD), a marker of immaturity, and CDKN2A/2B deletion have been identified as poor predictors of outcome in T-ALL treated with contemporary protocols. The aim of this study was to determine the correlation between ABD and CDKN2A/2B in Indian T-ALL patients. Methods: A total of 31 cases of T-ALL, diagnosed on morphology, cytochemistry and immunophenotyping, were included in the study. The age of the patients ranged from 1-50 years. The patients were investigated for CDKN2A/2B deletion by multiplex ligation dependent probe amplification (MLPA) using the commercially available probe set P383 (MRC Holland). The status of the deletion of TCR- γ was determined using quantitative assay described by Gutierrez et al.1 Results: Absence of biallelic deletion of TCR- γ gene were found in 14 (45.16%) patients. Homozygous deletion was seen in 13 (41.93%) patients while monoallelic deletion was seen in 5 (16.12%) patients. CDKN2A/2B deletions were found in (48.38%) patients. On correlation of CDKN2A/2B deletion and TCR- γ deletion, it was found that CDKN2A/2B deletion was found in 2/14 (14.28%) patients with ABD and 10/13 (76.92%) patients with homozygous deletion. Conclusions: CDKN2A/2B deletion are more common in patients with homozygous deletion of TCR- γ gene.
Evaluation of multiplex ligation dependent probe amplification (MLPA) for identification of acute lymphoblastic leukemia with an intrachromosomal amplification of chromosome 21 (iAMP21) in a Brazilian population