Molecular genetics and Cytogenetics data of 317 patients with de novo acute leukemia

Abstract

Background/Aims: Cytogenetic and molecular genetics play a pivotal role in treatment of acute leukemias. We prospectively evaluated genetic alterations in Brazilian patients with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) and their association with clinical and laboratorial data. Methods: Flow cytometry, conventional cytogenetics (CC), FISH, PCR, RT-PCR and sequencing were performed on samples from 161 de novo ALL and 155 AML.Results: Main CC findings in AML were t(15;17) (19.4%), +8 (17.4%), complex karyotype (14.6%), t(8;21) (7.6%); in ALL main CC findings were high hyperdiploidy (18.7%), low hyperdiploidy (9.7%), t(1;19) (9.7%), t(9;22) (8.2%). Frequencies of gene fusions and mutations in AML were PML-RARa 21.9%, RUNX1-RUNX1T1 7.1%, CBFB-MYH11 and MLL-AF9 2.6%, FLT3-ITD 14.2%, NPM1mut 13.6%. In ALL, ETV6-RUNX1 and BCR-ABL were present in 11.5% of the cases, TCF3-PBX1 in 10.8% and MLL-AF1 in 1.5%. Results were discordant between CC and RT-PCR in 3.6% of the cases. PML-RARa was associated with younger age, lower WBC and platelet; FLT3-ITD with higher hemoglobin and WBC; NPM1mut with higher platelet and WBC, older age and normal karyotype. BCR-ABL was associated with higher age; MLL-AF1 with higher WBC and EGIL BI-subtype. Conclusions:The incidence of some aberrations in AML differed from international literature. Discrepancies found between methodologies reinforce the importance of both CC and PCR in the diagnosis of leukemias.

Cytogenetic profile of Acute Myeloid Leukemia and Acute Lymphoblastic Leukemia in Northern Pakistan

“…These findings are in accordance with international literature. 21,22 A study representing the southern region of Pakistan also demonstrated increased frequency of Philadelphia chromosome in the adult ALL. 23 Similar findings were observed in Sudanese population.…”

“…This percentage is comparable with Brazilian study carried out by Compos C et al i.e., 45.8%. 21 Hyperdiploidy was the most frequently occurring chromosomal aberration with majority of the cases involving childhood and adolescence. Hyperdiploidy is a prognostically favorable abnormality.…”