Identification of a patient with 7q32 deletion-associated acute myeloid leukemia and an incidental t(8;14).

Constitutional activation of the MYC proto-oncogene resulting from a t(8;14) has been demonstrated in approximately 80% of Burkitt lymphoma patients, but only in one case of acute myeloid leukemia (AML). We report on a 59-year-old female diagnosed with minimally differentiated AML (M0). Chromosome analysis demonstrated both a 7q deletion and a t(8;14). Fluorescence in situ hybridization studies confirmed MYC/IGH fusion in 35% of nuclei, but the translocation was atypical due to lack of immunoglobulin heavy chain (IGH) gene disruption. Such an atypical fusion has never been reported, so the effect on MYC regulation due to proximity of IGH regulatory elements is unknown. Real-time polymerase chain reaction analysis demonstrated no increase in MYC expression (P = 0.12). These results suggest that this novel translocation does not result in dysregulation of MYC expression, so this is likely to be a coincidental, benign finding in this patient. This is yet another example of a classic cytogenetic abnormality observed on conventional chromosome analysis which has no functional significance.