TITLE:
Cytogenetic and Molecular Characterization of Hematological Neoplasm in an Ecuadorian Population
AUTHORS:
César Paz-y-Miño, María Eugenia Sánchez, Santiago Araujo, Ligia Ocampo, Víctor Hugo Espín, Paola E. Leone
KEYWORDS:
Hematological Diseases; Chromosomal Aberration; BCR-ABL; PML-RARA; CBFB-MYH11; MLL-AF4; Geographical Heterogeneity
JOURNAL NAME:
Open Journal of Blood Diseases,
Vol.3 No.4,
December
13,
2013
ABSTRACT: Cancer is one
of the major causes of mortality in Ecuador and annually, hematological
malignancies are within the top ten most common cancers. In this multicentric
study, we analyzed a series of patients diagnosed with
different hematological disorders between the years 1984 and 2012. Chromosome abnormalities
were detected in 1886 (45.9%) patients. FISH and RT-PCR techniques were used in
order to determine the presence of genetic rearrangements and complement
conventional cytogenetics results. Using FISH and RT-PCR, positive cases were
increased by 1.8% and 6.9% respec- tively. We
analyzed fusion genes resulting from t(8;21), t(15;17), inv(16), t(9;22), 11q23
rearrangements, t(4;11) and t(1;19). The frequency of transcripts of some of
these fusion genes was of particular interest as our results differ from studies
on other populations. Specifically, the fusion gene BCR-ABL was present in the form of the b2/a2 transcript in 95% of
CML patients and in the form of b3/a2 transcript in the remaining 5%. The PML-RARA fusion gene also showed a
distinct pattern of transcript expression. This fusion gene exhibited the bcr2
(36%) and bcr3 (64%) transcripts, how- ever the bcr1
transcript was absent from our sample population. All cases carrying the CBFB-MYH11 fusion gene ex- hibited the F transcript.
This was also of interest due to the rarity of this particular transcript
worldwide. Finally all cases carrying the MLL-AF4
fusion gene displayed the e7-e8 transcript. The frequency of the subtypes of
some fusion genes differ from those reported in other populations, possibly due
to the particular genetic make-up of the Ecuadorian population, mostly mestizo,
as well as environmental factors.