Características genéticas da leucemia promielocítica aguda de novo

Abstract

Acute promyelocytic leukemia (APL) is characterized by structural chromosomal abnormalities involving the RARα (retinoic acid receptor a) gene located on the long arm of chromosome 17 (17q21) that lead to the formation of chimeric genes and fusion oncoproteins. In about 98% of cases, the RARα gene is fused to the PML gene, the result of a reciprocal chromosomal translocation t(15;17)(q22;q21) and in the other 2% of cases the RARα gene may be fused to other genes, leading to the formation of fusion proteins known generically as X-RARα. Acute promyelocytic leukemia is an example of a hematologic malignancy where there is a combination of genetic and epigenetic (acetylation, deacetylation and methylation) changes in the leukemogenesis process, chromosome structural changes that affect the dynamic equilibrium of chromatin in the promoter region of some genes. The use of molecular techniques that improve genetic diagnosis and the development of targeted molecular therapy have provided a high cure rate of this disorder.