IGH rearrangements, (14q32) There are a number of stereotypical translocations involved in IGH (14q32) rearrangements associated with lymphoblastic leukemias. In B-ALL, IGH is most notably involved in rearrangements involving the cMYC oncogene as a result of the t(8;14) translocation. However, less common rearrangements of the IGH gene are most often seen in T-ALL, but can also be found in B-ALL (0.1% of the […]
TCF3-PBX1 fusion gene, t(1;19) t(1;19)(q23;p13) translocation event between the TCF3 locus (19p13.3) and PBX1 locus (1q23) which produces the chimeric gene TCF3-PBX1, is present in most type L1 and type L2 ALLs and exceptionally in ALL- L3. The translocation occurs in approximately 5% of childhood ALL and while this chromosomal anomaly usually was associated with poor prognosis, nowadays associates with
ABL-BCR translocation, t(9;22) The t(9;22)(q34;q11.2) translocation fuses ABL proto-oncogene on chromosome 9 with the BCR (breakpoint cluster region) region located on chromosome 22, leading to the formation of the Philadelphia chromosome (Ph) and the formation of two hybrid genes. The first gene is BCR-ABL (major), located on the long arm of chromosome 22 or chromosome
TEL/ETV6-AML1/RUNX1 fusion gene, t(12;21) t(12;21)(p13;q22) reciprocal translocation is the most frequent chromosomal rearrangement in childhood B-ALL with an incidence of 25% in children (only 3% occurs in adults). The expression of the resulting fusion gene TEL-AML1 or ETV6-RUNX1, leads to expansion of the precursors of B cells giving them a great capacity for self-renewal and differentiation to mature
12;21 – TEL(ETV6)-AML1(RUNX1) Read More »
MLL rearrangements, (11q23) MLL/ALL1/HRX gene (11q23) encodes a 90 amino acid protein and is highly expressed in the thymus, but not in peripheral lymphoid tissues. In contrast to its restricted normal hematopoietic tissue distribution, this gene is expressed in all leukemia cell lines studied. Chromosomal rearrangements of the human MLL gene are associated with acute leukemias
Mutations in BRAF Oncogenic mutations in the BRAF gene destroy the kinase domain, which results in constitutive activation of MAPK (mitogen-activated protein kinase) route, thereby stimulating the growth of abnormal cells. Activation of the MAPK pathway also occurs as a result of somatic mutations of other oncogenes, such as N-RAS. More than 30 mutations in
CCND1 amplification, (11q13) CCND1 gene encodes the protein CD1 (Cyclin D1), wich is deregulated in cancer, together with other D-type cyclins. CCND1 is considered a phenotype and disease progression marker. CCND1 amplification is a frequent event in some types of malignant melanomas and its pattern of altered expression can influence metastatic progression and survival, associated
Loss of MYB, (6q23) The MYB gene (Avian myeloblastosis Viral Oncogene Homolog) plays an essential role in regulating hematopoiesis and may be involved in tumorigenesis. This gene was chosen as a 6q marker due to its distal location to the breakpoints on 6q (6q21). This test detects the number of copies of the MYB gene
EGFR amplification, (7p12) EGFR, also known as HER1 / ERBB1, is a member of the EGFR family that also includes HER2 / ERBB2, HER3 / ERBB3 and HER4 / ERBB4 genes. The EGFR gene encodes a transmembrane glycoprotein with tyrosine kinase activity, which presumably plays a key role in the control of cell proliferation. EGFR
TP53 mutations Mutation of one allele of the P53 gene often involves deletion of the other allele and the result is the absence of the protein. Monoallelic deletion of P53 (determined by FISH) is found in many solid tumors, including breast, lung, skin, bladder, colon, cervical, ovarian and glioblastoma, among others, in addition to various
