Type I MOZ/CBP (MYST3/CREBBP) is the most common chimeric transcript in acute myeloid leukemia with t(8;16)(p11;p13) translocation.
The t(8;16)(p11;p13) fuses the MOZ (MYST3) gene at 8p11 with CBP (CREBBP) at 16p13 and is associated with an infrequent but well-defined type of acute myeloid leukemia (AML) that has unique morphocytochemical findings (monocytoid blast morphology with erythrophagocytosis and simultaneously positive for myeloperoxidase and nonspecific esterases). RT-PCR amplification of MOZ/CBP (MYST3/CREBBP) chimera has proved difficult, with four different transcripts found in four reported cases. We studied 7 AML-t(8;16) patients, 5 with cytogenetically demonstrated t(8;16) and 2 with similar morphocytochemical and immunophenotypical characteristics. Clinically, 3 cases presented as therapy-related leukemia. Extramedullar involvement was observed at presentation in 2 patients and coagulopathy in 4. The clinicobiological findings confirmed the distinctiveness of this entity. Of note is the erythrophagocytosis in 5 of 7 cases and the immunological negativity for CD34 and CD117 and positivity for CD56. Using a new RT-PCR strategy, we were able to amplify a specific band of 212 bp in six cases in which sequence analysis confirmed the presence of the previously described MOZ/CBP fusion transcript type I. This is the largest molecularly studied AML-t(8;16) series, which demonstrates that MOZ/CBP breakpoints are usually clustered in intron 16 of MOZ and intron 2 of CBP. The newly designed single-round PCR provides a simple tool for the molecular confirmation of MOZ/CBP rearrangement.
Rozman
María
M
Hematopathology Unit, Department of Pathology, Postgraduate School of Hematology Farreras-Valentí, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Barcelona, Spain. mrozman@clinic.ub.es
Camós
Mireia
M
Colomer
Dolors
D
Villamor
Neus
N
Esteve
Jordi
J
Costa
Dolors
D
Carrió
Ana
A
Aymerich
Marta
M
Aguilar
Josep Lluis
JL
Domingo
Alícia
A
Solé
Francesc
F
Gomis
Federico
F
Florensa
Lourdes
L
Montserrat
Emili
E
Campo
Elias
E
D000208:Acute Disease; D000328:Adult; D000368:Aged; D019457:Chromosome Breakage / Q000235:genetics; D002874:Chromosome Mapping; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D005260:Female; D006801:Humans; D007621:Karyotyping; D007951:Leukemia, Myeloid / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D014178:Translocation, Genetic / Q000235:genetics*
C470260:MOZ-CBP fusion protein, human; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion