Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043346 (xeroderma pigmentosum)
 2,924 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Xeroderma pigmentosum associated with neurological abnormalities is a less familiar neurocutaneous disorder. In this report, 35 patients with group A xeroderma pigmentosum were assessed for neurological complications. Of these, 17 showed microcephaly and 24 mental retardation. Of 25 patients over 7 years of age, 22 had sensorineural deafness and 12 showed spinocerebellar signs such as nystagmus, dysarthria, tremor and ataxia, while none below 7 years of age had such neurological complications. Thirty-five EEG studies were performed on 29 patients, and 15 showed intermittent spindles of grouped theta waves with abnormal slow background activity and a poorly developed alpha rhythm, suggesting immature brain development or a regression from normal brain function in many areas including the diencephalon. Twenty-six patients were examined by cranial CT scan, of whom 20 showed abnormal CT findings such as ventricular dilatation, diffuse cortical atrophy, and marked thickening of the calvarial bones. The incidence of abnormal EEG and CT findings increased with advancing age in accordance with the development of neurological complications in the CNS, thus suggesting a chronic progressive degenerative disease.
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PMID:EEG and CT abnormalities in xeroderma pigmentosum. 281 76

DNA repair mechanisms constitute major defences against agents that cause cancer, degenerative disease and aging. Different repair systems cooperate to maintain the integrity of genetic information. Investigations of DNA repair involvement in human pathology require an efficient tool that takes into account the variety and complexity of repair systems. We have developed a highly sensitive damaged plasmid microarray to quantify cell lysate excision/synthesis (ES) capacities using small amounts of proteins. This microsystem is based on efficient immobilization and conservation on hydrogel coated glass slides of plasmid DNA damaged with a panel of genotoxic agents. Fluorescent signals are generated from incorporation of labelled dNTPs by DNA excision-repair synthesis mechanisms at plasmid sites. Highly precise DNA repair phenotypes i.e. simultaneous quantitative measures of ES capacities toward seven lesions repaired by distinct repair pathways, are obtained. Applied to the characterization of xeroderma pigmentosum (XP) cells at basal level and in response to a low dose of UVB irradiation, the assay showed the multifunctional role of different XP proteins in cell protection against all types of damage. On the other hand, measurement of the ES of peripheral blood mononuclear cells from six donors revealed significant diversity between individuals. Our results illustrate the power of such a parallelized approach with high potential for several applications including the discovery of new cancer biomarkers and the screening of chemical agents modulating DNA repair systems.
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PMID:A microarray to measure repair of damaged plasmids by cell lysates. 1881 95

A large number of studies indicate that DNA damage and mutation increase with age in human cells and tissues (1). Age-related degenerative disorders in which DNA damage has been invoked include heart disease and neurodegenerative conditions such as Alzheimer's disease, amyotrophic lateral sclerosis, or Parkinson's disease (2, 3). Patients with deficiencies in DNA repair, including xeroderma pigmentosum (XP) (4) and ataxia-telangiectasia (A-T) (5) show characteristic patterns of neurodegeneration (as opposed to a failure of normal development). The implication is that failure of repair can lead to accumulation of damage and degenerative disease. XPs and A-Ts are hypersensitive to specific types of DNA damage, and the degenerative damage in patients is tissue specific. DNA in every tissue, however, is under attack from a range of endogenously formed mutagens, including reactive oxygen species, nitric oxide, reactive metabolites, and breakdown products such as malondialdehyde. A series of repair enzymes recognize and remove these types of DNA damage from the genome. Failure to repair DNA may cause the synthesis of defective proteins, which will repair DNA less efficiently, and in turn lead to propagation of further errors (6). Alternatively, oxidative damage to mitochondrial proteins might cause less efficient processing of oxygen, release of higher levels of reactive oxygen species and increased levels of background DNA damage.
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PMID:Measurement of DNA damage and repair capacity as a function of age using the comet assay. 2235 Dec 71