Molecular analysis of 1p32 genetic involvement in pediatric T-cell non-Hodgkin's lymphoma

Background and Objective. T-cell acute lymphoblastic leukemia (T-ALL) and l ymphoblastic T-cell non-Hodgkin's lymphoma (T-NHL) are closely related diso rders, and distinguishing between the two may be difficult. Cytogenetic Inv estigations of large NHL series reported different recurring chromosomal al terations. Among these, aberrations of chromosome Ip seem to be associated with T-cell differentiation, the region most frequently involved in breakpo ints being band 1p32-36. Deletions and translocations involving the same ch romosomal region are frequently observed in T-ALL, in which one of the most common genetic changes is the breakage of the TAL1 gene, mapped to the 1p3 2 chromosomal region. The objective of this study was to assess the possibi lity of TAL1 involvement also in T-NHL. Design and Methods. A series of 17 pediatric T-NHL patients was molecularly characterized by microsatellite markers analysis and by TAL1 gene microdel etions. Results. TAL1 gene rearrangement was found in one case, while loss of heter ozygosity (LOH) and microsatellite instability (MI) was identified in anoth er case. Interpretation and Conclusions. Overall our findings indicate that, differe ntly from T-ALL, neither TAL1 gene Involvement nor LOH or MI at 1p32 appear particularly relevant in the oncogenic process of T-NHL transformation. (C )1999, Ferrata Storti Foundation.