A unique structural abnormality of chromosome 16 resulting in a CBF beta-MYH11 fusion transcript in a patient with acute myeloid leukemia, FAB M4.
A 43-year-old female with a peripheral white cell count of 118.0 x 10(9)/L and 96% blasts was diagnosed with acute myeloid leukemia (AML), FAB M4. Cytogenetics, performed on a bone marrow sample, revealed the following abnormal karyotype: 46,XX,ins(16)(q22p13.1p13. 3). Fluorescence in situ hybridization (FISH) confirmed the inter-arm insertion using a probe for 16p. The result of this structural rearrangement was the fusion of CBF beta to MYH11 seen commonly in inv(16)(p13q22). The patient commenced high-dose intensive combination chemotherapy (big ICE; Idarubicin, Cytarabine, and Etopiside). Five days post chemotherapy, she developed febrile neutropenia. Despite broad spectrum intravenous antibiotics and antifungal therapy, the patient died at day nine post chemotherapy. This case demonstrates a previously unreported structural abnormality of chromosome 16 in a patient with AML M4, which represents a third mechanism to inv(16)(p13q22) and t(16;16)(p13q22) in producing the CBF beta-MYH11 fusion. CBF beta-MYH11 fusions masked by cryptic translocations at the cytogenetic level have been detected by FISH and PCR techniques. Due to the improved prognosis associated with CBF beta-MYH11 fusions compared to the standard risk group for AML, its detection remains important.
O'Reilly
J
J
Department of Haematology, Royal Perth Hospital, Perth, Australia.
Chipper
L
L
Springall
F
F
Herrmann
R
R
D000328:Adult; D001853:Bone Marrow / Q000648:ultrastructure; D002869:Chromosome Aberrations / Q000235:genetics*; D007446:Chromosome Inversion; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D005260:Female; D006801:Humans; D007621:Karyotyping; D015479:Leukemia, Myelomonocytic, Acute / Q000235:genetics*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
C095514:CBFbeta-MYH11 fusion protein; D015514:Oncogene Proteins, Fusion; D012334:RNA, Neoplasm