We found that TWIST2 was inactivated in more than 50% of cases of childhood and adult acute lymphoblastic leukemia through promoter hypermethylation and that this epigenetic regulation was especially prevalent in RUNX1-ETV6-driven cases.
In comparison with Western cohorts, the incidence of t(9;22) (q34;q11)/BCR-ABL (14.60%) in B-ALL and HOX11 expression in T-ALL (25.24%) seemed to be much higher in our group, while the incidence of t(12;21) (p13;q22)/ETV6-RUNX1 (15.34%) seemed to be lower in Chinese pediatric patients.
This study reports three new cases (aged 8 months, 5 years, and 33 years) of ALL with the ETV6/ABL1 fusion found by screening 392 newly diagnosed ALL patients (335 children and 57 adults).
We reviewed data from 2811 children with ALL enrolled in Children's Oncology Group P9900, which included prospective testing for the major cytogenetic lesions in childhood ALL: ETV6-RUNX1, TCF3-PBX1, BCR-ABL1, and MLL translocations and trisomies of chromosomes 4 and 10.
In this cohort of Taiwanese children, the relative frequencies of the 4 translocations of B-lineage ALL were 8% with ALL-type t(9;22)/BCR-ABL1, 4% with (1;19)/TCF-PBX1, 2% with t(4;11)/MLL-AF4, and 17.6% with t(12;21)/ETV6-RUNX1.
This study describes the cytogenetics of 33 children with ETV6-RUNX1 positive acute lymphoblastic leukemia (ALL) who had been in continuous complete remission for a minimum of 8.8 years [median event-free survival (EFS) 10.9 years].
Compared to Europe, the ALL population in Nicaragua is older, has a higher proportion of poor prognostic clinical and hematological features and receives more intensive treatment, while patients with TEL/AML1 translocations and high-hyperdiploidy are clinically in the standard risk group.
Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, with high hyperdiploidy [51-67 chromosomes] and the t(12;21)(p13;q22) [ETV6/RUNX1 fusion] representing the most frequent abnormalities.
In children with TEL/AML1 positive ALL relapse, additional (a) TEL loss, (b) combined AML1 and der(21) gain, (c) combined TEL loss and AML1 gain as well as (d) the occurrence of a subpopulation with the signal pattern 1T/3A/1TA appear to be related to higher peripheral blast counts (PBCs) at relapse diagnosis (a and d) or a tendency towards the occurrence of a subsequent relapse (b and c) (P-values <0.05).
The deleted segment on 12p contains several genes, among the tumor suppressor genes ETV6 and CDKN1B, which are frequently involved in 12p abnormalities in childhood ALL.
In the current study (26 cases), the frequencies of the most frequent genetic rearrangements TEL-AML1, MLL/AF4, BCR-ABL (major and minor) in ALL in children from Mexico City were determined.
We evaluated the prevalence of BCR/ABL, MLL, and ETV6/RUNX1 rearrangements as well as CDKN2A (alias p16) deletion in a group of Mexican children with acute lymphoblastic leukemia (ALL) to determine whether the changes coexist, and to compare the incidences found with other reports in the literature.
We screened 1,625 patients who were enrolled onto the Austrian and German ALL-Berlin-Frankfurt-Münster (ALL-BFM) trials 86, 90, 95, and 2000 with ETV6/RUNX1-specific fluorescent in situ hybridization probes, and we identified 29 patient cases (2%) who had an iAMP21.
A large-cohort study (619) of acute lymphoblastic leukemia (ALL) revealed an ETV6/RUNX1 (previously known as TEL/AML1) incidence of 18% in pediatric B-cell precussor ALL, indicating no geographical heterogeinity.
In 288 children with ALL, cellular ASNS expression was more likely to be high in T-lineage ALL and low in B-lineage ALL with TEL-AML1 or hyperdiploidy.
We observed a consistently higher (2.8-fold) expression of OPAL1 in TEL-AML1-positive ALL compared with TEL-AML1-negative ALL in both cohorts, but higher OPAL1 expression was not consistently associated with other favorable prognostic indicators such as age and white blood cell count, or ALL genetic subtype.