PML-RARalpha fusion gene transcripts and biological features in acute promyelocytic leukemia patients

Abstract

Acute promyelocytic leukemia (APL) is characterized by the presence of rearrangements involving the retinoic acid receptor alpha (RARalpha) gene and a variable incidence in different populations. The hybrid gene PML-RARalpha, present in 98% of cases, encodes a fusion protein essential to the pathogenesis of the disease. Depending of the PML's gene breakpoint in chromosome 15, the transcript subtypes bcr1, bcr2 and bcr3 may be formed. The correlation between these transcript subtypes and clinical parameters is still controversial. The objective of this study was to determine the frequencies of the PML-RARalpha transcripts and subtypes in a series of 32 APL patients from Northeast Brazil and to evaluate the association of these subtypes to different parameters. The method used was RT-PCR. The frequency of our APL cases is approximately 28% of the acute leukemias. The results showed the presence of PML-RARalpha isoform in all patients and a higher frequency of the bcr1/2 subtype. No significant statistical association was found between molecular subtypes and age, sex, French-American-British (FAB) classification, leukocyte and platelet count, hemoglobin level or coagulation tests. In conclusion, these data suggest similar molecular and biological features for our APL patients at diagnosis in comparison with those reported in current scientific literature.

Epidemiology and Treatment of Acute Promyelocytic Leukemia in Latin America

“…We have reported that APL represents 28.2% of all AML cases in centers in Brazil, a number that is very similar to the reported by Melo, R et al (28%) 13. This is ratified by information from Mexico (20%), 12 Venezuela (27.8%)14 and Peru (22%) 15.…”

Geographic Hematology: Some Observations in Mexico

“…Latin Americans living in the USA have a greater frequency of APL compared to the the non-Latin American Caucasian population (i.e., 24.3 vs. 8.3% and age 31.5 vs. 46 years in Latin Americans vs. non-Latin Americans, respectively, as observed by Douer et al [31]). This finding has also been observed in other Latin American countries such as Brazil (28.2%) [32,33], Venezuela (27.8%) [34], and Peru (22%) [35]. The geographic variation suggests a possible genetic predisposition or environmental exposures to specific risk factors.…”

A Retrospective Study of Acute Promyelocytic Leukemia

“…The confirmatory test for the diagnosis of Acute promyelocytic Leukemia is the molecular study of PML-RARᾳ i.e. t(15:17).After analysing the data 19 cases were found PML-RARᾳ positive while two cases were found PML-RARᾳ negative and also HLA-DR negative and the morphology suggest Acute promyelocytic leukemia (Fig 7 & table 7).The result of our study is similar as the study conducted by Melo RA, et al 2006 andGustavo J et al, 2002,where they found PML-RARA positive in 98% cases.…”