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

Abstract

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.