Identification of the TAF15-ZNF384 fusion gene in two new cases of acute lymphoblastic leukemia with a t(12;17)(p13;q12).

We report the clinical, cytogenetic, and molecular data of two patients diagnosed with acute lymphoblastic leukemia characterized by the rare translocation t(12;17)(p13;q12). This translocation has been reported in 25 cases and its putative molecular consequence, the formation of a TAF15-ZNF384 fusion gene, in only six cases. We used fluorescence in situ hybridization followed by long-range polymerase chain reaction to find the translocation breakpoints. A fusion between TAF15 and ZNF384 was identified and confirmed by nucleotide sequencing. Our results confirm that the t(12;17)(p13;q12) leading to a TAF15-ZNF384 fusion gene characterizes a specific subgroup of acute lymphoblastic leukemia and suggest that two different breakpoints in TAF15 may be involved. Whether the two variants of the TAF15-ZNF384 fusion that these correspond to are in any way hematologically or prognostically different, is unknown.