Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Trichothiodystrophy (TTD) is a rare, autosomal recessive disorder characterized by sulfur-deficient brittle hair and nails, mental retardation, impaired sexual development, and ichthyosis. Photosensitivity has been reported in approximately 50% of the cases, but no skin cancer is associated with TTD. Virtually all photosensitive TTD patients have a deficiency in the nucleotide excision repair (NER) of UV-induced DNA damage that is indistinguishable from that of xeroderma pigmentosum (XP) complementation group D (XP-D) patients. DNA repair defects in XP-D are associated with two additional, quite different diseases; XP, a sun-sensitive and cancer-prone repair disorder, and Cockayne syndrome (CS), a photosensitive condition characterized by physical and mental retardation and wizened facial appearance. One photosensitive TTD case constitutes a new repair-deficient complementation group, TTD-A. Remarkably, both TTD-A and XP-D defects are associated with subunits of TFIIH, a basal transcription factor with a second function in DNA repair. Thus, mutations in TFIIH components may, on top of a repair defect, also cause transcriptional insufficiency, which may explain part of the non-XP clinical features of TTD. Besides XPD and TTDA, the XPB gene product is also part of TFIIH. To date, three patients with the remarkable conjunction of XP and CS but not TTD have been assigned to XP complementation group B (XP-B). Here we present the characterization of the NER defect in two mild TTD patients (TTD6VI and TTD4VI) and confirm the assignment to X-PB. The causative mutation was found to be a single base substitution resulting in a missense mutation (T119P) in a region of the XPB protein completely conserved in yeast, Drosophila, mouse, and man. These findings define a third TTD complementation group, extend the clinical heterogeneity associated with XP-B, stress the exclusive relationship between TTD and mutations in subunits of repair/transcription factor TFIIH, and strongly support the concept of "transcription syndromes."
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PMID:A mutation in the XPB/ERCC3 DNA repair transcription gene, associated with trichothiodystrophy. 901 5

Six known or predicted helicases that are mutated in human syndromes are now recognized. These syndromes include xeroderma pigmentosum, Cockayne's syndrome, trichothiodystrophy, Bloom's syndrome, Werner's syndrome, and alpha-thalassemia mental retardation on the X chromosome. The clinical abnormalities in these syndromes cover a broad spectrum, pointing to different cellular processes of DNA manipulation that are defective in these syndromes.
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PMID:DNA helicases in inherited human disorders. 922 11

We report an autopsy case of Cockayne syndrome (CS). A 40-year-old Japanese woman was admitted to our hospital for cachexia. She had displayed the striking features of CS, including dwarfism, mental retardation, neural deafness, ataxia, intracranial calcifications, and progeria since her childhood. Endocrinological examinations suggested normal pituitary function and a disorder of the hypothalamus or the cerebrum. She died of acute pneumonia at the age of 42. Autopsy findings showed typical abnormalities in the central nervous system compatible with CS; however, no atherosclerotic change was observed in the systemic arteries.
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PMID:An adult case of Cockayne syndrome without sclerotic angiopathy. 926 Jul 74

A 12-year-old girl developed ataxia that gradually progressed. At age 18 the patient presented with mental retardation, cachectic dwarfism, microcephalus, and a progeroid appearance but no photosensitive skin lesions or deafness. On analysis of fibroblasts, unscheduled DNA synthesis was reduced to 50% of normal, but colony-forming ability after ultraviolet irradiation was normal. The symptoms and phenotype of the patient were distinguished from those in Cockayne syndrome and xeroderma pigmentosum. This case is interesting because the defect in DNA repair after ultraviolet irradiation was detected in a patient with neurologic disturbances but without photosensitive skin lesions.
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PMID:A DNA repair defect in a patient with ataxia, mental retardation, and short stature. 958 36

Cockayne syndrome (CS) is a rare autosomal recessive disorder characterized by postnatal growth failure, mental retardation and otherwise clinically heterogeneous features which commonly include cutaneous photosensitivity. Cultured cells from sun-sensitive CS patients are hypersensitive to ultraviolet (UV) light and, following UV irradiation, are unable to restore RNA synthesis rates to normal levels. This has been attributed to a specific deficiency in CS cells in the ability to carry out preferential repair of damage in actively transcribed regions of DNA. We report here a cellular and molecular analysis of three Italian CS patients who were of particular interest because none of them was sun-sensitive, despite showing most of the features of the severe form of CS, including the characteristic cellular sensitivity to UV irradiation. They all were altered in the CSB gene. The genetically related patients CS1PV and CS3PV were homozygous for the C1436T transition resulting in the change Arg453opal. Patient CS2PV was a compound heterozygote for two new causative mutations, insertions of an A at position 1051 and of TGTC at 2053, leading to truncated proteins of 367 and 681 amino acids. These mutations result in severely truncated proteins, as do many of those that we previously identified in several sun-sensitive CS-B patients. These observations confirm that the CSB gene is not essential for viability and cell proliferation, an important issue to be considered in any speculation on the recently proposed additional function of the CSB protein in transcription. Our investigations provide data supporting the notion that other factors, besides the site of the mutation, influence the type and severity of the CS clinical features.
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PMID:Alterations in the CSB gene in three Italian patients with the severe form of Cockayne syndrome (CS) but without clinical photosensitivity. 1019 84

Cockayne syndrome is a rare autosomal recessive progressive neurological disorder characterized by a nanism, a major cachexy, a characteristic facial appearance of premature ageing, a sun-sensitivity, a retinopathy, and a mental retardation. We report three observations of Cockayne syndrome. The diagnostic criteria, notably clinical, found in these patients are discussed in comparison to the literature.
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PMID:[Cockayne syndrome in Lebanon. Description of 3 cases and review of the literature]. 1041 Apr 72

Cockayne's syndrome is a very rare autosomal recessive affection. Ocular involvement is an essential element for positive diagnosis; the retina shows a typical salt and pepper retinitis with optical atrophy. We report a family with four brothers who had Cockayne's syndrome with unusual retinal involvement. The patients' parents were first cousins. Ophthalmologic examination of the mother showed unilateral left pigmentary retinopathy localized in the peripapillary region. The father's ophthalmological examination was normal. The four brothers presented disharmonious dwarfism, cutaneous hyperpigmentation of skin areas exposed to sun with old-appearance of the skin, sensorineural deafness, kyphoscoliosis, a cerebellar syndrome and mental retardation. The ophthalmological examination showed hypermetropia in all four brothers and bilateral maculopathy with no papillary or vascular abnormalities. The electroretinogram was in favor of cone dystrophy. Computed tomography showed one case of calcifications of the basal ganglia and cerebral atrophy. The karyotypes of the four brothers and the mother were normal. We discuss the ocular symptoms and the etiopathogenesis of this syndrome.
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PMID:[Cockayne's syndrome with unusual retinal involvement (report of one family)]. 1066 Jun 49

Mutations in the human CSB gene cause Cockayne syndrome (CS). In addition to increased photosensitivity, CS patients suffer from severe developmental abnormalities, including growth retardation and mental retardation. Whereas a deficiency in the preferential repair of UV lesions from the transcribed strand accounts for the increased photosensitivity of CS patients, the reason for developmental defects in these individuals has remained unclear. Here we provide in vivo evidence for a role of RAD26, the counterpart of the CSB gene in Saccharomyces cerevisiae, in transcription elongation by RNA polymerase II, and in addition we show that under conditions requiring rapid synthesis of new mRNAs, growth is considerably reduced in cells lacking RAD26. These findings implicate a role for CSB in transcription elongation, and they strongly suggest that impaired transcription elongation is the underlying cause of the developmental problems in CS patients.
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PMID:Requirement for yeast RAD26, a homolog of the human CSB gene, in elongation by RNA polymerase II. 1171 97

Cockayne's syndrome is a disease of childhood characterized by mental retardation and premature aging. An 11-year-old girl with Cockayne's syndrome underwent general anesthesia for acute appendicitis. Although we had expected the difficulty of intubation because of her small jaw with limited movement, we could visualize her vocal cord, and intubate easily. High peak airway pressure was needed to ventilate her lung after intubation suggesting decreased lung compliance for this syndrome. We have to consider anesthetic problems resulting not only from pediatric but also from geriatric anesthesia for the management of this syndrome.
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PMID:[Anesthetic management of a patient with Cockayne's syndrome]. 1175 30

Cockayne's syndrome is a rare, inherited, autosomal recessive disorder, characterised by dwarfism and progressive physical and mental retardation. A case is described of a 6-year-old girl (height 75 cm, weight 5.0 kg) with Cockayne's syndrome who was scheduled for liver biopsy under general anesthesia. Anesthesia was induced using 5% sevoflurane combined with 67% nitrous oxide in oxygen. After the end-tidal sevoflurane concentration of 3.5% had been maintained for 10 minutes, laryngoscopy was attempted. The vocal cord was visualised and the trachea was intubated easily without muscle relaxant. Anesthesia was maintained with sevoflurane and nitrous oxide in oxygen. The procedure lasted for 13 minutes. The tracheal tube was removed uneventfully following the return of adequate spontaneous respiration and airway reflexes. There were no postoperative problems. Concerning Cockayne's syndrome, there have been some reports of difficult airway, laryngospasm, aspirations of gastric contents and others. It is important to prevent laryngospasm by keeping the adequate depth of anesthesia for endotracheal intubation.
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PMID:[Anesthesia for a patient with Cockayne's syndrome]. 1184 Jun 61


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