Genetic chromosomal translocations

Genetic Control. Manipulation of the mechanisms of inheritance of the insect pest populations has occurred most successhiUy through the mass release of steri1i2ed males, but a variety of other techniques have been studied, including the environmental use of chemostetilants and the mass introduction of deleterious mutations, eg, conditional lethals and chromosomal translocations (58 ndash 60) (see Genetic engineering). 

The presence of chromosomal translocations is a consistent feature of many leukemia s, lymphomas, and certain solid tumors. At the genetic level, these events can either deregulate an intact gene by disruption or removal and replacement of the adjacent controlling elements, or create a new fusion gene that express the N-terminus of one protein fused to the C-terminus of another protein. 

Figure 2. Genetic aberrations observed in HAT genes, (a) Schematic representation of a balanced chromosomal translocation. These translocations result in the formation two new fusion genes, which can give rise to one or two fusion proteins, (b) Examples of nonsense (RTS patient RT163.1), missense (RT209.1), deletion (followed by frame shift RT231.1) mutations, as well as sphee site acceptor (RT211.3) or splice site donor (RT39.1) mutations...

As in cancer predisposing syndromes, these genetic alterations are sometimes carried in the germline. Among human tumours, heritable mutations are an exception. Most alterations are acquired in somatic life in the form of chromosomal translocations, deletions, inversions, amplifications or point mutations. Certain oncogenic viruses play important roles in a few human tumours. Examples are human papilloma-virus in cervical cancer and skin tumours, Ep-stein-Barr virus in nasopharyngeal carcinoma and Burkitt s lymphoma, and human T-cell leukaemia viruses (e.g. HTLV-I, HTLV-II) in T-cell leukaemia. 

Chromosomal translocations are frequently associated with specific types of cancer. This is direct evidence that genetic abnormalities can lead to cancer. 

Halauska, F. G., Y. Tsujimoto, and C. M. Croce, Oncogene activation by chromosome translocation in human malignancy. Ann Rev. Genet. 21 321-345, 1987. 

Benet, J Oliver-Bonet, M., Cifuentes, R, Templado, C and Navarro, J., Segregation of chromosomes in sperm of reciprocal translocation carriers a review, Cytogenet. Genome Res. Ill, 281-290, 2005 Apian, P.D., Causes of oncogenic chromosomal translocation. Trends in Genetics 22,46-55, 2006. 

C. H., and Alt, F.W., Mechanism and control of V(D)J recombination versus class switch recombination similarities and differences, Adv. Immunol. 86, 43-112, 2005 Aplon, P.D., Causes of oncogeific chromosomal translocation. Trends Genet. 22, 46-55, 2006. 

The concomitant occurrence of additional genetic aberrations and chromosomal translocations is common in hematological malignancies. The HAS oncogene is one of the most frequently mutated genes in cancer,and is mutated in up... 

A EXPERIMENTAL FIGURE 10-29 Chromosomal translocations can be analyzed using banding patterns and multicolor FISH. Characteristic chromosomai translocations are associated with certain genetic disorders and specific types of cancers. For example, in nearly all patients with chronic myelogenous leukemia, the leukemic cells contain the Philadelphia chromosome, a shortened chromosome 22 [der... 

PFG can vastly simplify genetic analysis as demonstrated in its application to analysis of yeast chromosomal translocations. 

Briefly, a chromosomal translocation involves the transposition and attachment of a piece of one chromosome onto another. Translocations are not infrequent genetic events and occur in virtually every organism including man. However, studying these events in organisms whose chromosomes cannot be visualized by light microscopy used to... 

The neoplastic transformation begins after a sequence of different acquired genetic mutations in the cellular genome, which include mutations within the gene sequences and different types of chromosomal abnormalities. Chromosomal translocations are one of the most important and interesting types of chromosomal abnormalities associated with neoplasia. 

Different cytogenetic abnormalities are found in many types of AML, w hich also include non-random chromosomal translocations specific for many AML subtypes and associated w ith different biological behavior and clinical outcome. The follow ing translocations are the most common specific genetic abnormalities associated w ith different AML subtypes ... 

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