Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fibroblasts derived from patients with diseases affecting DNA repair processes, such as Xeroderma Pigmentosum (classical and variant), Fanconi's anemia, Bloom's syndrome, Ataxia Telangiectasica, Progeria and Werner's syndrome, were assayed for the three DNA polymerases. The specific activities of these enzymes were found within the limits observed in normal human fibroblasts. Also the sedimentation properties of the three polymerases were unaltered.
 ...
PMID:DNA polymerases alpha beta and gamma in inherited diseases affecting DNA repair. 67 49

Fanconi-Zinsser's disease is a serious involutive myelopathy responsible for pancytopenia, hyperpigmentation, oralplakia and onychodystrophy, together with lesser dysmorphisms in many cases. The marrow blood picture is reminiscent of the better-known Fanconi's disease, while the skin and mucosa picture is similar to that of congenital dyskeratosis - hence the combined name. A typical case, but complicated by Lewandowsky's disease for the first time in the literature, is presented. Papova-virus was noted in the typical verrucae. The modern "pathology due to genome instability" is examined. Lewandowsky's disease is regarded as a familial form and precancerous, owing to its possible Bowenoid transformation. The association is seen as particularly significant in stressing the disorder of the immunocompetent syste, this being most evident from the finding of serum anti-red-cell auto-antibodies and a deficiency of T lymphocytes. Fanconi-Zinsser's disease has only been reported 21 times in the literature, mostly in males. Incomplete forms are, however, noted in relatives, suggesting that it originates in a genetic disorder whose transmission modality is not clear, though incomplete dominance is suspected. Genome instability is probably responsible behind the onset of the disease and its neoplastic complications - these being also feature of other forms provoked by such instability, such as Bloom's syndrome and ataxia telengiectasia. Fanconi's disease also has marked neoplastic tendencies. Clinically, Fanconi-Zinsser's disease can be classified as distinct, since it has signs and an evolutive modality that distinguish it from Franconi's disease, Estren-Damesheck's syndrome and amegakaryocytic thrombocytopenia. Genetically, it can be seen that all these diseases are referable to "pathology due to genome instability".
 ...
PMID:[Fanconi-Zinsser disease]. 86 9

Ataxia telangiectasia, Bloom's syndrome and normal fibroblasts were compared as to the capacity of their cellular extracts to enhance the priming activity of gamma-irradiated colicin E1 DNA for purified DNA polymerase. It was found that an ataxia strain had substantially lower, and a Bloom's syndrome strain had slightly lower capacity than a normal strain; while the activities of apurinic site specific endonuclease in these extracts were comparable.
 ...
PMID:DNA repair enzymes in ataxia telangiectasia and Bloom's syndrome fibroblasts. 92 14

Molecular epidemiology may help fill the gap between epidemiological and biological models for cancerogenesis, allowing useful comparisons between series of cases carrying different biological characteristics. The defective regulation of immune responses is probably the common basis of cancer origin in genetically determined immune deficiency (GDID). Lymphomas are the most common neoplasms, showing an extremely high incidence in early age, frequent unusual location (extra-nodal) and histology, and rapid progression and spread with little response to therapy. A high incidence of lymphoma is also found in acquired (AIDS) or iatrogenic (transplant recipients) immune defective patients. The emergence of a malignant clone may be linked to unregulated polyclonal B- or T-cell proliferation and to disturbances in chromosomal rearrangements and in clonal selection, which are unique features of the immune cells regulation. It is useful to compare patterns of malignancies observed in GDIDs and in chromosomal breakage syndromes (CBS). In ataxia-teleangectasia (AT), selective errors at sites of special recombination involved in immune cell rearrangements may account for both immune deficiency and frequent types of malignant transformation. Different cytogenetic alterations and different types of malignancies are more common in Bloom syndrome, and in other GDIDs unrelated to chromosomal fragility, possibly due to different regulatory impairments. Viral infection (EBV, HPV, CMV) is likely to be a factor in any of the above steps. Therefore, individual exposure to viral (or other environmental) agents may be related to frequent location (skin, ano-genital areas, digestive tracts) of nonlymphatic cancers both in some GDIDs and in acquired or iatrogenic immune deficiencies. Cells that are homozygous for GDID are not malignant themselves, but are more likely to undergo new mutations to malignancy, due both to disregulation of the immune system and to environmental agents.
 ...
PMID:Molecular epidemiology of cancer in immune deficiency. 203 52

Sixty-eight human fibroblast cell strains were assayed for radioresistant DNA synthesis (RDS), which is defined here as the absence of a steep component of inhibition of DNA synthesis in a dose-response curve when rate of DNA synthesis is plotted against radiation doses from 0 to 20 Gy or more. Twenty-seven strains from patients who were previously diagnosed to have ataxia-telangiectasia (AT) were positive for this feature. Among the cell strains that did not show RDS were two from AT obligate heterozygotes (i.e., the parents of AT patients), two from patients with Alzheimer disease, two from patients with Friedreich ataxia, one from a patient with Bloom syndrome, one from a patient with Down syndrome, and six from patients with various immunodeficiencies. Four strains demonstrated RDS that was less pronounced than in most AT cells: one was from a patient with Nijmegen breakage syndrome, one was from a patient without ataxia but with choreiform movement disorder, telangiectasia, and elevated concentrations of alpha-fetoprotein in the blood, and two were from AT patients. RDS therefore is not a necessary trait of human genetic diseases that involve radiosensitivity or immunodeficiency. Although recent reports suggest that some AT patients do not exhibit RDS, we found RDS in all the AT cells we tested.
 ...
PMID:Radioresistant DNA synthesis and human genetic diseases. 272 85

In this paper, a survey is given of the immunological disturbances in some chromosome instability disorders (e.g. Bloom syndrome, ataxia teleangiectasia and Nijmegen Breakage syndrome). Further, the clinical symptoms and the diagnostic approach will be discussed.
 ...
PMID:[Immunodeficiency and chromosome instability]. 320 18

About 5% of Mendelian mutations displaying neoplastic tendencies are associated with chromosomal aberrations. The best established examples are retinoblastoma and del(13)(q14) and aniridia-Wilms' tumor and del(11)(p13). Evidence suggests that both mutations behave as dominant traits in the individual and as recessive traits in the cells. DNA analysis indicates that tumorigenesis arises from homozygosisty for the mutant allele at these loci, as a consequence of mitotic nondisjunction or from a mitotic recombination event. An additional argument for this conclusion is provided by the demonstration of duplication of 11p15 in some patients with the Beckwith-Wiedemann syndrome, which is complicated often by Wilms' tumor and other embryonal tumors. Data obtained with molecular probes have shown that also rhabdomyosarcoma and hepatoblastoma arise by homozygosity for a mutant allele at a locus on 11p, suggesting ontogenic relatedness of these tumor types. Additional examples of Mendelian mutations associated with chromosome deletions and neoplasia include Langer-Giedion syndrome with multiple exostoses and del(8)(q24.1), multiple endocrine neoplasia and del(20)(p12.2). While the presence of specific chromosome changes in subjects with high susceptibility to neoplasia does pinpoint the location of DNA sequences involved in the predisposition to certain types of cancers, selected Mendelian mutations associated with chromosome instability and cancer proneness may elucidate biological principles of cell proliferation and transformation. However, our current knowledge of mechanisms resulting in increased frequency of chromosome breakage and cancer susceptibility in ataxia-teleangiectasia, Fanconi's anemia, Bloom's syndrome, and similar conditions are still very incomplete.
 ...
PMID:Cytogenetics of Mendelian mutations associated with cancer proneness. 382 76

The real cause of genetic instability, which is the hall-mark of most cancers, is poorly understood. Specific gene mutations and acquired aneuploidy have been implicated as the root causes of genetic instability. Here we propose and cite evidence for the hypothesis that genetic instability of cancer cells is caused by telomere dynamics, erosion and/or amplification of the TTAGGG repeat sequences present at chromosomal termini. Since telomeres determine the domain of individual chromosomes within a nucleus and protect them from internal and external challenges, their erosion will destabilize the cell karyotype. Our hypothesis predicts that telomere dynamics provides the single unifying mechanism playing a major role in speciation, aging and cancer development. It was found that metastatic cancers of different histologic phenotypes, as well as mammalian taxa with active speciation and larger numbers of species exhibit amplification of their telomeric DNA as compared to non-metastatic counterpart cancers and taxa with only a limited number of species. The dynamic nature of this DNA can be found not only in the cancer cells but also in the peripheral lymphocytes of cancer patients. Human syndromes such as Down, Turner, Bloom, Werner, Fanconi, ataxia and many others, show aneuploidy and also are prone to develop various malignancies and premature aging. We have found that <normal cells> of all these syndromes have a reduced amount of telomeric DNA associated with specific mitotic catastrophes as compared to cells of age- and sex-matched normal individuals. From these and additional data generated by our group concerning speciation, aging and cancer karyotypes, we conclude that aneuploidy, which is responsible for birth defects, cancer initiation and is a major player in natural speciation, is a consequence of telomere dynamics. Because telomere reduction is linked to the aging process, which is a risk factor for cancer development in the human population, our hypothesis offers a unifying mechanism for the initiation of both hematologic and solid cancers, as well as for the origin of new species.
 ...
PMID:Telomere dynamics, aneuploidy, stem cells, and cancer (review). 1183 81

Bloom's syndrome (BS) is a rare genetic disorder characterized by a broad range of symptoms and, most importantly, a predisposition to many types of cancers. Cells derived from patients with BS exhibit an elevated rate of somatic recombination and hypermutability, supporting a role for bleomycin (BLM) in the maintenance of genomic integrity. BLM is thought to participate in several DNA transactions, the failure of which could give raise to genomic instability, and to interact with many proteins involved in replication, recombination, and repair. In this study, we show that BLM function is specifically required to properly relocalize the RAD50/MRE11/NBS1 (RMN) complex at sites of replication arrest, but is not essential in the activation of BRCA1 either after stalled replication forks or gamma-rays. We also provide evidence that BLM is phosphorylated after replication arrest in an Ataxia and RAD3-related protein (ATR)-dependent manner and that phosphorylation is not required for subnuclear relocalization. Therefore, in ATR dominant negative mutant cells, the assembly of the RMN complex in nuclear foci after replication blockage is almost completely abolished. Together, these results suggest a relationship between BLM, ATR, and the RMN complex in the response to replication arrest, proposing a role for BLM protein and RMN complex in the resolution of stalled replication forks.
 ...
PMID:Bloom's syndrome protein is required for correct relocalization of RAD50/MRE11/NBS1 complex after replication fork arrest. 1191 80

There exist numerous genetic disorders, marked by chromosome instability, that are strikingly associated with various cancers. Both the chromosomal instabilities and neoplastic outcomes are related to abnormalities of DNA metabolism, DNA repair, cell-cycle governance, or control of apoptosis. Among these diseases are ataxia telangectasia and Nijmegen breakage syndrome, with increased incidences of lymphomas. Bloom syndrome, Werner syndrome, and Rothmund-Thompson syndrome, each characterized by a DNA helicase defect, are associated with early incidences of different cancers. Other diseases combining the phenotype of chromosomal instabilities and neoplastic development are Fanconi anemia and breast cancers associated with mutant BRCA1 and BRCA2 genes. The cloning of the encoding genes and the characterization of their products have resulted in partial understanding of the pathways of cellular DNA surveillance and maintenance of genomic rectitude. The exact pathways fully linking the genetic defect mechanisms to the eventual development of various neoplasias remain to be elucidated, but progress in defining the molecular genetics of these entities suggests that many of them are disorders of DNA recombination. Each defect involves a separate protein in these complex pathways.
 ...
PMID:Chromosome breakage syndromes and cancer. 1240 92


1 2 Next >>