HMGA2 overexpression in polycythemia vera with t(12;21)(q14;q22).
Chromosomal translocations involving the 12q14 band are rarely detected in hematological disorders, and are usually correlated with HMGA2 gene expression. HMGA2 is highly expressed during embryonic cell growth and differentiation, and regulates transcription and chromatin organization, but is rarely detectable in adult tissues. We describe a case of polycythemia vera with a t(12;21)(q14;q22). The 12q14 breakpoint was characterized by fluorescence in situ hybridization analysis using the bacterial artificial chromosome RP11-366L20 containing 3' sequences of the HMGA2 gene. Qualitative and quantitative polymerase chain reaction showed the presence of high levels of HMGA2 gene expression, which were temporarily reduced with hydroxyurea therapy. The present case confirms that involvement of the 12q14 band may be associated with HMGA2 overexpression in chronic Philadelphia chromosome-negative myeloproliferative disease, regardless of the partner chromosome involved in the translocation. Such overexpression may contribute to the pathogenesis of the disease, which otherwise of itself shows a favorable and stable course.
Aliano
Stefania
S
Laboratory of Cytogenetics, Department of Internal Medicine, University of Genoa, V.le Benedetto XV-6, 16132 Genoa, Italy.
Cirmena
Gabriella
G
Garuti
Anna
A
Fugazza
Giuseppina
G
Bruzzone
Roberto
R
Rocco
Ilaria
I
Malacarne
Michela
M
Ballestrero
Alberto
A
Sessarego
Mario
M
D000368:Aged; D002871:Chromosome Banding; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D005260:Female; D025743:HMGA2 Protein / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D010677:Philadelphia Chromosome; D011087:Polycythemia Vera / Q000235:genetics*; D014158:Transcription, Genetic; D014178:Translocation, Genetic
D025743:HMGA2 Protein