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)

A 4-year-old female with Cockayne syndrome presented for cataract extraction under general anesthesia. She was thin and frail; her neck, epiglottis and larynx were stiff; she was deaf and blind; and she could not speak, sit unaided, or perspire. At the time of her admission, she weighed 5.5 kg. Cockayne syndrome is a disease of childhood characterized by mental retardation and premature aging. Although the underlying abnormality appears to be autosomal recessive inheritance or metabolic (possibly thymic) dysfunction, there is no consensus on etiology. The multiple organ involvement carries significant implications for the anesthetist. Intubation can be technically difficult, and care of the skin can be problematic. Essential hypertension, hepatic deficiencies, osteoporosis, deafness, blindness, and other effects of premature aging may be encountered making perioperative management a challenge.
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PMID:Cockayne syndrome: a case report. 781 Feb 87

Cockayne's syndrome (CS) is a rare autosomal recessive premature-aging disorder which is clinically characterized by physical and mental retardation, retinal pigmentation, sensorineural deafness and other neurological abnormalities. Auditory brainstem responses (ABRs) and behavioral audiometry were studied in 4 cases of confirmed CS chronologically. In one case, ABRs were normal at first but became abnormal. Initially, ABRs revealed only wave I with prolonged latency and thereafter no response. In another case, ABRs revealed the absence of all waves beyond wave III and then revealed the disappearance of all waves. In 2 other cases, ABRs were absent from the first testing. Behavioral levels were elevated in all 4 cases. In 2 cases, behavioral levels did not change in spite of partial disappearance of ABR waves, but they had elevated severely since all waves including wave I disappeared. Our findings suggest that the disease spreads from the upper brainstem to the cochlear nerve and that the site of the lesion causing hearing loss in CS is in the brainstem lesion as well as the peripheral one.
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PMID:Chronological changes of auditory brainstem responses in Cockayne's syndrome. 783 34

Trichothiodystrophy (TTD), an autosomal recessive disorder characterized by sulfur-deficient brittle hair, identifies a group of genetic disorders with an altered synthesis of high-sulfur matrix proteins and a defect in excision repair of ultraviolet damage in fibroblasts of most TTD patients. In contrast to patients with xeroderma pigmentosum (XP), TTD patients do not have an increased frequency of skin cancers. TTD patients may be grouped into four categories: 1) those without photosensitivity and without a defect in excision repair of UV damage; 2) those without photosensitivity and with an excision-repair defect in the same gene as in XP-D (complementation group D); 3) those with photosensitivity and with the XP-D repair defect; 4) those with photosensitivity and with a repair defect distinct from that in XP-D. We present a brother and sister in the third category of TTD. Clinically, the patients have brittle hair, short stature, ichthyosis, photosensitivity, nail and dental dysplasias, cataracts, mental retardation, and pyramidal tract abnormalities. Diagnosis was made by hair mount, which shows the characteristic banding pattern with polarizing microscopy, and by hair amino acid analysis, which demonstrated decreased high-sulfur matrix proteins. Fibroblasts cultured from skin biopsies had a marked DNA excision repair defect similar to the repair defect seen in XP-D. We have documented a unique dysmyelinating disorder on magnetic resonance imaging of the brain that might explain their mental retardation, marked hyperactivity, and neurologic deficits. Following the discovery that the human excision repair cross complementing rodent ultraviolet group 2 (ERCC2) gene is able to correct the ultraviolet sensitivity of XP-D cell strains, the ERCC2 cDNA from previous TTD patients was sequenced and shows frameshifts, deletions and point mutations in the ERCC2 gene. Molecular analysis of our patients is in progress. Molecular analysis of the defects in ERCC2 in clinically distinct patients with XP,XP/Cockayne's syndrome, and TTD may provide insight into the molecular mechanisms of these genetically related but clinically distinct disorders.
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PMID:Trichothiodystrophy: clinical spectrum, central nervous system imaging, and biochemical characterization of two siblings. 796 80

Cockayne syndrome is a rare autosomal recessive disorder of childhood characterized by cachectic dwarfism with senile-like appearance, mental retardation, photosensitive dermatitis, loss of adipose tissue, pigmentary degeneration of retina, microcephaly, deafness, skeletal and neurologic abnormalities. We describe here an 18 year old boy with Cockayne syndrome who had, in addition to the typical features of the disorder, fasting hyperinsulinemia and growth hormone deficiency.
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PMID:Cockayne syndrome: a case with hyperinsulinemia and growth hormone deficiency. 806 22

A 9-year-old girl with characteristic clinical signs of Cockayne's syndrome type I (cachectic dwarfism, "senile" like appearance, mental retardation, progressive neurologic and retinal degeneration) is presented. Computerized tomography and magnetic resonance imaging of the brain have shown a large malformation in cerebral posterior fossa. The case also has unusual aspects: pronounced congenital hypertrichosis and dark pigmented teeth. To our knowledge, these signs have never been described in the literature in connection with this rare syndrome.
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PMID:[Cockayne syndrome]. 864 15

Cells from Cockayne's syndrome (CS) patients are sensitive to ultraviolet light and defective in preferential repair of the transcribed DNA strand. CS patients suffer from complex clinical symptoms, including severe growth retardation, neurological degeneration, mental retardation, and cachexia. Two CS complementation groups, CSA and CSB, have been identified so far. RAD26 encodes the yeast counterpart of the CSB gene. Here, we purify Rad26 protein to near homogeneity from yeast cells and show that it is a DNA-dependent ATPase. In contrast to the Mfd protein that functions in transcription-coupled repair in Escherichia coli, and which is a weak and DNA independent ATPase, Rad26 is a much more active ATPase, with a strict dependence on DNA. The possible role of Rad26 ATPase in the displacement of stalled RNA polymerase II from the site of the DNA lesion and in the subsequent recruitment of a DNA repair component is discussed.
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PMID:RAD26, the yeast homolog of human Cockayne's syndrome group B gene, encodes a DNA-dependent ATPase. 870 68

Cockayne's syndrome is a rare, autosomal recessive condition which usually presents in early childhood, and is characterised by dwarfism, premature ageing, mental retardation and a typical facial appearance and body habitus. Retinal dystrophy, enophthalmos, strabismus, cataract, nystagmus and corneal opacities are associated ocular features. At a genetic level, a defect occurs in the pathway for the repair of transcriptionally active DNA, and the most common form of Cockayne's is associated with mutations in the human repair gene ERCC6. These patients pose a difficult management problem. A significant proportion will require cataract extraction at an early age, which may present technical difficulties due to enophthalmos, which is a constant finding, poor pupillary dilation and growth retardation. Also, the fitting and assessment of aphakic contact lenses during the post-operative period requires great skill. General anaesthesia in these patients may be hazardous. In particular, difficulty with endotracheal intubation should be anticipated. Two patients with Cockayne's syndrome requiring bilateral cataract extraction in early infancy are presented. The problems associated with surgery, anaesthesia and subsequent follow-up in these mentally retarded infants are discussed.
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PMID:Ophthalmic management of Cockayne's syndrome. 876 5

Cockayne syndrome (CS) is an autosomal recessive disorder with dwarfism, mental retardation, sun sensitivity and a variety of other features. Cultured CS cells are hypersensitive to ultraviolet (UV) light, and following UV irradiation, CS cells 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 repair damage in actively transcribed regions of DNA at the rapid rate seen in normal cells. We have used the failure of recovery of RNA synthesis, following UV irradiation of CS cells, in a complementation test. Cells of different CS donors are fused. Restoration of normal RNA synthesis rates in UV-irradiated heterodikaryons indicates that the donors are in different complementation groups, whereas a failure to effect this recovery implies that they are in the same group. In an analysis of cell strains from 22 CS donors from several countries and different racial groups, we have assigned five cell strains to the CS-A group and the remaining 17 to CS-B. No obvious racial, clinical or cellular distinctions could be made between individuals in the two groups. Our analysis will assist the identification of mutations in the recently cloned CSA and CSB genes and the study of structure-function relationships.
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PMID:Genetic analysis of twenty-two patients with Cockayne syndrome. 883 35

A 10-year-old girl complained or poor vision in both eyes. The patient showed progeria, physical and mental retardation, sensorineural hearing loss, cutaneous photosensitivity, hyperopia, poor pupillary dilation, exotropia, salt-and-pepper fundi, nondetectable cone and rod electroretinographic (ERG) responses, cerebral atrophy on computed tomography, and demyelination of periventricular white matter on magnetic resonance imaging. We believe that nondetectable cone and rod ERG responses in Cockayne syndrome, as demonstrated in our patient, may be uncommon.
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PMID:Nondetectable cone and rod electroretinographic responses in a patient with Cockayne syndrome. 892 50

Clinical and laboratory findings of 25 patients with classical Cockayne syndrome (CS) are reviewed. A history of consanguinity was present in 21 patients, and 15 patients had at least 1 affected sibling. Apart from the cardinal features of dwarfism, microcephaly, and mental retardation, the most consistent clinical features included photosensitivity (84%), gait disturbances (84%), progeroid appearance (84%), and ocular abnormalities (88%). The most consistent laboratory findings comprised abnormal nerve conduction (slowed conduction in 13 of the 16 cases with an ENMG), and an abnormal brainstem auditory evoked response (BAER) and/or audiometry (abnormal in 13 of the 17 cases in whom either one of them were available). Cerebral atrophy and calcification of the basal ganglia were the next more common laboratory findings. Clinical criteria are useful in most instances in the diagnosis of CS. In patients in whom the clinical features are controversial for a diagnosis of Cockayne syndrome, studies directed to disorders of myelination involving both peripheral and central nervous systems in conjunction with audiometry may aid in the diagnosis.
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PMID:Cockayne syndrome: review of 25 cases. 897 30


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