OUTCOME AND LINEAGE INVOLVEMENT IN T(12-21) CHILDHOOD ACUTE LYMPHOBLASTIC-LEUKEMIA

The t(12;21)(p13;q22) translocation has been described recently as the most recurrent genetic lesion in paediatric acute lymphoblastic leuka emias (ALLs). It has also been associated with B-precursor lineage inv olvement and good outcome. We tested 51 diagnostic paediatric ALLs and found 11 cases with molecular evidence of the t(12;21). Interestingly , amongst t(12;21) positive patients, we report three cases with hybri d phenotype, and two cases showing an aggressive and fatal disease. Ou r data show that the t(12;21) does not represent an independent good-r isk indicator. Long follow-ups and additional molecular Investigations are needed to assess the prognostic and pathogenetic relevance of t(1 2;21) in childhood ALLs.