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)

The average number of diagnostic x-ray procedures per year in the United States equals the total population and results in an annual collective effective dose equivalent of about 9 million person-rem. Possible deleterious effects include (a) genetic consequences, the risks of which can be assessed only from animal studies; (b) carcinogenesis, which can be assessed from survivors of nuclear bombings and patients exposed for medical reasons; and (c) effects on the developing embryo or fetus. For stochastic endpoints such as cancer and genetic anomalies, it is estimated that the current practice of radiology in the United States increases spontaneous frequency by less than 1%. No single procedure is likely to produce harm to the conceptus, but an accumulation of procedures in a pregnant woman could be hazardous during the sensitive period of 8-15 weeks after conception, with microcephaly and mental retardation the most likely deleterious effects. The balance of risk versus benefit in diagnostic radiology is heavily weighted toward benefit, but the risks are there, and constant efforts are needed to reduce radiation doses to the minimum necessary.
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PMID:Scientific view of low-level radiation risks. 185 43

Forty-nine cases of isolated familial and idiopathic gingival fibromatoses, consisting of 12 cases from six families and 37 cases of idiopathic gingival fibromatosis, were reviewed. Pedigrees of five families revealed various penetrances and genetic heterogeneity as suggested by the presence of both autosomal dominant and autosomal recessive inheritances. Ultrastructurally, the lesions were composed of fibroblast-like cells and myofibroblast-like cells, with the former being the predominant cell type. The 267 cases of familial and idiopathic gingival fibromatoses were analyzed, and they with or without hypertrichosis, mental retardation, and/or epilepsy. These included 49 cases seen by the authors, 50 cases from the Japanese literature, and 168 cases from non-Japanese literature. Isolated gingival fibromatosis occurred more frequently after age of 12 years (P less than 0.0074). There was no significant difference in age of onset between generalized and localized forms of the idiopathic gingival fibromatosis. Gingival fibromatosis with hypertrichosis and mental retardation and/or epilepsy occurred frequently before 12 years (P less than 0.069). It has been shown that heterogeneity of the gingival fibromatosis is a result of either histologic heterogeneity, genetic heterogeneity, or a combination with other systemic disorders.
Cancer 1991 Nov 15
PMID:Heterogeneity in the gingival fibromatoses. 191 58

Mortality rates for institutionalized persons with mental retardation were presented. Rates were provided for two time intervals, 1974 through 1979 and 1980 through 1985, and by age, race, and gender. Consistent differences between black and white residents or by gender were not indicated. However, significant improvement in mortality did occur between the two time periods. Persons with profound retardation were found to have higher mortality than those whose retardation was mild to severe. Respiratory disease was the most prevalent cause of death among the individuals with profound mental retardation, whereas heart disease and cancer were the most common causes of death among persons with mild, moderate, or severe retardation. Aging of the population was noted over the period of the study, indicative of the increasing frailty of the institutionalized population.
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PMID:Mortality in a large southeastern facility for persons with mental retardation. 200 9

Photosensitive genodermatoses associated with established defects of DNA repair currently include the autosomal recessive diseases xeroderma pigmentosum (XP), Cockayne's syndrome (CS), trichothiodystrophy (TTD), and Bloom's syndrome (BS). XP is a heterogeneous disorder associated with defective excision repair or daughter strand repair of ultraviolet (UV)-induced DNA damage. It is characterized by cutaneous and ocular abnormalities predominantly on sun-exposed sites and in some cases, neurological features resulting from progressive neuronal loss. Skin involvement includes easy sunburning, pigmentary abnormalities, telangiectasia, dryness, scarring, and susceptibility to multiple benign and malignant neoplasms. In CS, defective repair of actively transcribing DNA is clinically associated with acute photosensitivity, growth retardation, demyelinating neurological abnormalities, and pigmentary retinal degeneration, but without increased cancer susceptibility. TTD is characterized by sulphur-deficient brittle hair, variable growth delay, mental retardation, ichthyosis, and in some cases photosensitivity. Although in some patients there is a deficiency of DNA excision repair identical to that in certain xeroderma pigmentosum patients, no increased cancer risk is present in trichothiodystrophy. In BS, deficient cellular DNA ligase is associated with congenital telangiectasia, photosensitivity, growth retardation, immune deficiency, increased susceptibility to infection, and predominantly internal rather than cutaneous malignancy. Immunological factors may at least determine the varying susceptibility to malignancy of these conditions.
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PMID:DNA repair deficient photodermatoses. 220 44

Family histories of male patients with histologically confirmed malignant gliomas were compared to family histories of controls (wives). Included were 77 case families with 892 relatives and 77 control families with 719 relatives. Cases had significantly more siblings than controls (P = 0.02), although cases were not preferentially the oldest or the youngest sibs. Odds ratios of two or more were found for mental retardation, Parkinson's disease, and meningitis for the relatives of cases versus controls, but none were statistically significant. The excesses of Parkinson's disease and meningitis were explained by the family of one particularly interesting case containing three relatives with meningitis and two relatives with Parkinson's disease. Noteworthy age-adjusted odds ratios for cancer among relatives of cases compared to relatives of controls were 1.6 (95% confidence interval (CI) = 1.0-2.3) for cancer of any site, 2.4 (95% CI = 0.8-6.1) for breast cancer, and 4.0 (95% CI = 0.6-10.7) for lung cancer. Only the odds ratio for cancer of any site was statistically significant. Overall, 6 of 77 (8%) of cases came from families that included two or more relatives with breast or lung cancer in addition to the proband with malignant glioma. These three cancer sites may form familial clusters worthy of further evaluation in future studies by pedigree and genetic linkage analyses.
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PMID:Familial factors associated with malignant gliomas. 222 74

Gestational and familial risk factors were investigated for their association with astrocytoma, the most frequently occurring brain tumor in children. A case-control study of 163 matched pairs was performed. Cases under 15 years of age at diagnosis in 1980-1986 were identified through the tumor registries of 8 hospitals in Pennsylvania, New Jersey, and Delaware. Controls were selected by random digit dialing and were matched to cases for age, race, and telephone area code and exchange. Maternal antinausea medications increased the risk of childhood astrocytoma [OR (odds ratio) = 2.0, P = 0.04]. Cured meat consumption during pregnancy was more common among cases (OR = 1.9, P = 0.07), and a significant trend with increasing frequency of consumption was observed (P = 0.04). Results for gestational exposure to marijuana (OR = 2.8, P = 0.07) were of borderline significance. Gestational exposure to neurally active medications, alcohol, and tobacco were not risk factors. There was a significant trend for cases to be of higher birth weight (P = 0.03). Mental retardation (OR = 3.0, P = 0.04) and cancer (OR = 1.7, P = 0.02) in a relative of the child significantly increased the risk of astrocytoma. Significantly increased risks were observed for brain tumors in relatives of children 0-4 years of age at diagnosis (OR = 6/0, P = 0.04). A significant protective effect was observed for maternal history of miscarriage or stillbirth (OR = 0.5, P = 0.01). The results of this study suggest that some gestational and familial factors may increase the risk of childhood astrocytoma.
Cancer Res 1990 May 01
PMID:Gestational and familial risk factors for childhood astrocytoma: results of a case-control study. 232 86

Of 77 patients with supratentorial Grades I and II astrocytoma diagnosed from January 1975 to December 1984, 66 were treated with postoperative radiation therapy. The patients received a tumor dose of 5000 to 5500 cGy in 180 cGy fractions, five fractions per week, over 5.5 to 6 weeks. Overall actuarial survival at 2, 5, and 10 years was 71%, 55%, and 43%, respectively. Progression-free survival at 2, 5, and 10 years was 69%, 50%, and 39%, respectively. Survival for patients receiving postoperative radiation therapy in the range of 4500 to 5900 cGy was 78% and 66% at 2 and 5 years, respectively. Quality of life was determined at two points in time: 1 to 2 years postoperatively, and at last follow-up (2-12 years postoperatively). The occurrence of mental retardation was specifically addressed in long-term survivors, and was observed in 50% of children. Overall, however, 80% of short-term survivors and 67% of long-term survivors were intellectually and physically intact, without major neurologic deficit. Specific prognostic factors were assessed by multivariate analysis. Improved survival was observed with young patients, females, normal preoperative mental status, surgical resection (versus biopsy alone), involvement of only one lobe with tumor, and a history of preoperative seizures. A weighted prognostic factor score derived from these observations permits a clinically useful assessment of risk for individual patients.
Cancer 1990 Jul 01
PMID:Low-grade cerebral astrocytomas. Survival and quality of life after radiation therapy. 235 9

The short arm of chromosome 11 carries genes involved in malformation syndromes, including the aniridia/genitourinary abnormalities/mental retardation (WAGR) syndrome and the Beckwith-Wiedemann syndrome, both of which are associated with an increased risk of childhood malignancy. Evidence comes from constitutional chromosomal aberrations and from losses of heterozygosity, limited to tumor cells, involving regions 11p13 and 11p15. In order to map the genes involved more precisely, we have fused a mouse cell line with cell lines from patients with constitutional deletions or translocations. Characterization of somatic cell hybrids with 11p-specific DNA markers has allowed us to subdivide the short arm into 11 subregions, 7 of which belong to band 11p13. We have thus defined the smallest region of overlap for the Wilms' tumor locus bracketed by the closest proximal and distal breakpoints in two of these hybrids. The region associated with the Beckwith-Wiedemann syndrome spans the region flanked by two 11p15.5 markers, HRAS1 and HBB. These hybrids also represent useful tools for mapping new markers to this region of the human genome.
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PMID:Characterization of a panel of somatic cell hybrids for subregional mapping along 11p and within band 11p13. Subdivision of the WAGR complex region. 272 95

A 6-year-old boy whose chief complaint was retentio testis was referred to our clinic. He had mental retardation, shortness of stature of prenatal onset, retarded growth, microbrachycephaly, bushy eyebrows, long eyelashes, low-set ears and micromelia, and was diagnosed to have Cornelia de Lange syndrome. As in most cases of Cornelia de Lange syndrome the cause of our case was not clear, and chromosome analysis showed a 46,XY constitution. In our case, we performed bilateral orchidopexy for retentio testis because of the problem of fertility and the danger of malignancy. Cornelia de Lange syndrome is rare and the urologic literature dealing with this disease has never been reported in Japan. The clinical features of this disease are discussed in the present report.
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PMID:[A case of Cornelia de Lange syndrome with retentio testis]. 286 86

One in 10,000 children develops Wilms' tumour, an embryonal malignancy of the kidney. Although most Wilms' tumours are sporadic, a genetic predisposition is associated with aniridia, genito-urinary malformations and mental retardation (the WAGR syndrome). Patients with this syndrome typically exhibit constitutional deletions involving band p13 of one chromosome 11 homologue. It is likely that these deletions overlap a cluster of separate but closely linked genes that control the development of the kidney, iris and urogenital tract (the WAGR complex). A discrete aniridia locus, in particular, has been defined within this chromosomal segment by a reciprocal translocation, transmitted through three generations, which interrupts 11p13. In addition, the specific loss of chromosome 11p alleles in sporadic Wilms' tumours has been demonstrated, suggesting that the WAGR complex includes a recessive oncogene, analogous to the retinoblastoma locus on chromosome 13. In WAGR patients, the inherited 11p deletion is thought to represent the first of two events required for the initiation of a Wilms' tumour, as suggested by Knudson from epidemiological data. We have now isolated the deleted chromosomes 11 from four WAGR patients in hamster-human somatic cell hybrids, and have tested genomic DNA from the hybrids with chromosome 11-specific probes. We show that 4 of 31 markers are deleted in at least one patient, but that of these markers, only the gene encoding the beta-subunit of follicle-stimulating hormone (FSHB) is deleted in all four patients. Our results demonstrate close physical linkage between FSHB and the WAGR locus, suggest a gene order for the four deleted markers and exclude other markers tested from this region. In hybrids prepared from a balanced translocation carrier with familial aniridia, the four markers segregate into proximal and distal groups. The translocation breakpoint, which identifies the position of the aniridia gene on 11p, is immediately proximal to FSHB, in the interval between FSHB and the catalase gene.
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PMID:The beta-subunit of follicle-stimulating hormone is deleted in patients with aniridia and Wilms' tumour, allowing a further definition of the WAGR locus. 301 43


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