TEL is a new member of the ETS family of transcription factors which is rearranged in a number of hematologic malignancies with translocations involving chromosome band 12p13.
Two known genes map within the critically deleted region of 12p: TEL, the gene encoding a new member of the ETS family of transcription factors, which is rearranged in a variety of hematological malignancies; and KIP1, the gene encoding the cyclin-dependent kinase inhibitor p27.
Heterogeneity in the breakpoints in balanced rearrangements involving band 12p13 in hematologic malignancies identified by fluorescence in situ hybridization: TEL (ETV6 ) is involved in only one half.
The human TEL gene is involved in several 12p13 chromosomal abnormalities present in various human hematological malignancies, the most frequent being the t(12;21)(p13;q22), specific for childhood acute lymphoblastic leukemia.
The translocation results in the fusion of two known genes, ETV6/TEL(12p13) and AML1(21q22), both of which have been shown to be involved in other hematological malignancies.
The TEL/AML1 fusion does not occur in children with AML and suggests that the TEL/AML1 rearrangement is restricted in pediatric hematologic malignancy to B lineage ALL.
FISH analyses and loss of heterozygosity studies have delineated a commonly deleted region in hematological malignancies flanked by ETV6 and CDKN1B on chromosome 12p12.3.
Fusions of the ETV6/TEL gene to receptor or protein tyrosine kinases (TKs), such as PDGFRbeta, JAK2, ABL, ABL2, TRKC, and Syk, have been reported in various hematological malignancies.
HDAC9 interacts and co-localizes in vivo with a number of transcriptional repressors and co-repressors, including TEL and N-CoR, whose functions have been implicated in the pathogenesis of hematological malignancies.
This case reiterates the importance of correlating morphologic and phenotypic findings with the results of cytogenetic analysis to avoid errors in diagnosing hematologic neoplasms and highlights the rare association of B-cell non-Hodgkin lymphoma with aberrations of TEL.
Alterations of the short arm of chromosome 12 (12p) occur in various hematologic malignancies and ETV6 and CDKN1B, which are located on 12p, have been implicated as leukemogenic genes of interest.