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 first case in the dental literature of congenital contractural arachnodactyly (C.C.A. syndrome) is presented. This newly delineated syndrome is an autosomal dominant heritable disorder of connective tissue. Its similarities to Marfan's syndrome and homocystinuria, as well as other syndromes, are discussed. The lack of cardiovascular disease, specific ocular anomalies, and mental retardation are presented in the differential diagnosis of the C.C.A syndrome with Marfan's syndrome and homocystinuria.
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PMID:The C.C.A. syndrome (congenital contractural arachnodactyly): a new differential syndrome for Marfan's syndrome and homocystinuria. 105 23

Nonsyndromic familial supravalvular aortic stenosis is an autosomal dominant disorder. However, for many reported families, systematic study of all family members with echocardiographic or hemodynamic techniques has not been performed and degree of penetrance has not been assessed. The supravalvular stenosis in these family members usually is not associated with mental retardation or other characteristics of Williams syndrome. Although some believe that autosomal dominant supravalvular aortic stenosis is part of the spectrum of Williams syndrome, others believe that these are separate entities. Doppler echocardiograms were analyzed on 23 members of a 34 member family with several known to have supravalvular aortic stenosis; 20 studies were performed by the authors and 3 were done elsewhere and made available for review. No family member had mental retardation, characteristic facies or other findings of Williams syndrome. Three of the 34 had supravalvular aortic stenosis requiring surgery. Of 22 members examined echocardiographically who had not had prior surgical repair, 13 had supravalvular aortic stenosis. Echocardiographic findings ranged widely, from calcification of the ascending aorta in a 71 year old man with minimally increased flow velocity (1.7 m/s) to mild narrowing with mildly increased flow velocity in six members to significant narrowing with impressively increased flow velocity (2 to 4 m/s) in seven. In addition, four patients had mild narrowing of pulmonary artery branches and eight had peak pulmonary artery flow velocity above normal. This study demonstrates complete penetrance with extremely variable expression in this family with autosomal dominant supravalvular aortic stenosis and emphasizes the importance of using echocardiographic techniques in studying the family members who are suspected of having an inherited cardiovascular disease.
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PMID:Spectrum of findings in a family with nonsyndromic autosomal dominant supravalvular aortic stenosis: a Doppler echocardiographic study. 291 19

Screening revealed a significantly higher incidence of hyperlipoproteinaemia in mentally retarded children in an Institute for Social Welfare than in the healthy child population (P 1%). In the aetiology participate most markedly secondary influences ensuing in particular from complications of the basic diagnosis of oligophrenia. It is mainly a question of the action of antiepileptics, neuroleptics, the influence of viral hepatic infections and other endogenous and exogenous factors. Early diagnosis of hyperlipoproteinaemia is possible so far only by biochemical methods. It is essential for genetic counselling, for prevention of deterioration as regards mental retardation, restriction of pharmacotherapy and later for a reduced risk of development of cardiovascular disease.
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PMID:[Hyperlipoproteinemia in mentally retarded children]. 840 35

Williams syndrome (WS) is characterized by distinct facial changes, growth deficiency, mental retardation, and congenital heart defect (particularly supravalvular aortic stenosis), associated at times with infantile hypercalcemia. Molecular genetic studies have indicated that hemizygosity at the elastin locus (7q11.23) causes WS. The purpose of this study was to confirm that this regional deletion, involving the elastin locus, is the cause of WS in Japan, and to clarify the correlation between the phenotype and the elastin locus. Thirty-two patients with WS and thirty of their relatives were examined by fluorescent in situ hybridization (FISH), using the WS chromosome region (WSCR) probe. All patients had cardiovascular disease (100%), 30 had typical WS facial changes (94%), 31 had mental retardation or developmental delay (97%), 16 were small-for-date at birth (50%), 14 had short stature (44%), and 13 had dental anomalies (41%). No relatives showed any manifestation of WS. Hemizygosity for a region of 7q11.23, involving the elastin locus, was found in all WS patients, but was not found in the 30 relatives.
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PMID:Molecular cytogenetic diagnosis of Williams syndrome. 886 24

Williams syndrome (WS) is a recognizable pattern of malformation with mental retardation, mild growth deficiency, characteristic facies and temperament, and cardiovascular disease. Sudden death is a recognized complication of WS; however, it is thought to be rare. The clinical features of 10 children with WS who died suddenly are reported here, doubling the number of unexpected deaths reported in the literature. We suggest that sudden death is a more common complication than has been assumed previously. Pathologic findings on the seven autopsy cases implicate two anatomic abnormalities that predispose individuals with WS to sudden death: coronary artery stenosis and severe biventricular outflow tract obstruction. The mechanisms for sudden death for both anatomic subgroups include myocardial ischemia, decreased cardiac output, and arrhythmia. We believe these observations warrant the development of strategies for monitoring patients with WS in an attempt to identify those at increased risk of sudden death.
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PMID:Sudden death in Williams syndrome: report of ten cases. 896 40

Homocystinuria due to cystathionine beta-synthase (CBS) deficiency, inherited as an autosomal recessive trait, is the most prevalent inborn error of methionine metabolism. Its diverse clinical expression may include ectopia lentis, skeletal abnormalities, mental retardation, and premature arteriosclerosis and thrombosis. This variability is likely caused by considerable genetic heterogeneity. We investigated the molecular basis of CBS deficiency in 29 Dutch patients from 21 unrelated pedigrees and studied the possibility of a genotype-phenotype relationship with regard to biochemical and clinical expression and response to homocysteine-lowering treatment. Clinical symptoms and biochemical parameters were recorded at diagnosis and during long-term follow-up. Of 10 different mutations detected in the CBS gene, 833T-->C (I278T) was predominant, present in 23 (55%) of 42 independent alleles. At diagnosis, homozygotes for this mutation (n=12) tended to have higher homocysteine levels than those seen in patients with other genotypes (n=17), but similar clinical manifestations. During follow-up, I278T homozygotes responded more efficiently to homocysteine-lowering treatment. After 378 patient-years of treatment, only 2 vascular events were recorded; without treatment, at least 30 would have been expected (P<.01). This intervention in Dutch patients significantly reduces the risk of cardiovascular disease and other sequelae of classical homocystinuria syndrome.
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PMID:The molecular basis of cystathionine beta-synthase deficiency in Dutch patients with homocystinuria: effect of CBS genotype on biochemical and clinical phenotype and on response to treatment. 1036 17

Alterations in homocysteine, methionine, folate, and/or B12 homeostasis have been associated with neural tube defects, cardiovascular disease, and cancer. Methionine synthase, one of only two mammalian enzymes known to require vitamin B12 as a cofactor, lies at the intersection of these metabolic pathways. This enzyme catalyzes the transfer of a methyl group from 5-methyl-tetrahydrofolate to homocysteine, generating tetrahydrofolate and methionine. Human patients with methionine synthase deficiency exhibit homocysteinemia, homocysteinuria, and hypomethioninemia. They suffer from megaloblastic anemia with or without some degree of neural dysfunction and mental retardation. To better study the pathophysiology of methionine synthase deficiency, we utilized gene-targeting technology to inactivate the methionine synthase gene in mice. On average, heterozygous knockout mice from an outbred background have slightly elevated plasma homocysteine and methionine compared to wild-type mice but seem to be otherwise indistinguishable. Homozygous knockout embryos survive through implantation but die soon thereafter. Nutritional supplementation during pregnancy was unable to rescue embryos that were completely deficient in methionine synthase. Whether any human patients with methionine synthase deficiency have a complete absence of enzyme activity is unclear. These results demonstrate the importance of this enzyme for early development in mice and suggest either that methionine synthase-deficient patients have residual methionine synthase activity or that humans have a compensatory mechanism that is absent in mice.
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PMID:Targeted disruption of the methionine synthase gene in mice. 1115 93

The association between physical activity, dietary behaviors, and elevated cardiovascular disease risk factor components of the insulin resistance syndrome in adults with mental retardation was identified. Established clinical cutoff points were used to identify 145 participants with mild mental retardation and hyperinsulinemia, borderline high triglycerides, low high-density lipoprotein cholesterol, hypertension, and abdominal obesity. Odds ratios were calculated from logistic regression analysis. Those who participated in more frequent bouts of physical activity or who consumed lower dietary fat intakes were approximately one third as likely to have hyperinsulinemia and abdominal obesity compared to those who participated in less frequent physical activity or who consumed higher fat intakes, suggesting that these behaviors are protective against elevated components of the insulin resistance syndrome.
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PMID:Physical activity, dietary intake, and the insulin resistance syndrome in nondiabetic adults with mental retardation. 1218 77

A population-based cohort of 10-year-old children with mental retardation, cerebral palsy, epilepsy, hearing impairment or vision impairment, who were ascertained at 10 years of age in a previous study conducted in metro Atlanta during 1985-87, was followed up for mortality and cause of death information. We used the National Death Index to identify all deaths among cohort members during the follow-up period (1985-95). We estimated expected numbers of deaths on the basis of actual age-, race- and sex-specific death rates for the entire Georgia population for 1989-91. The objective was to quantify the magnitude of increased mortality and evaluate the contribution of specific disabilities to mortality among children and adolescents with one or more of five developmental disabilities. A total of 30 deaths were observed; 10.1 deaths were expected, yielding an observed-to-expected mortality ratio of almost three to one. The numbers of observed deaths exceeded those of expected deaths, regardless of the number of disabilities present, but the ratios were statistically significant (at the 95% confidence level) only in children with three or more co-existing disabilities. In general, the magnitude of the mortality ratios was directly related to various measures of the severity of the person's disability. An exception to this pattern was the elevated mortality from cardiovascular disease among cohort members with isolated mental retardation (three observed deaths vs. 0.2 expected). The specific underlying causes of death among other deceased cohort members included some that were the putative cause of the developmental disability (e.g. a genetic syndrome) and others that could be considered intercurrent diseases or secondary health conditions (e.g. asthma). Prevention efforts to decrease mortality in adolescents and young adults with developmental disabilities may need to address serious conditions that are secondary to the underlying disability (i.e. infections, asthma, seizures) rather than towards injuries, accidents and poisonings, the primary causes of death for persons in this age group in the general population.
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PMID:Increased mortality in children and adolescents with developmental disabilities. 1244 56

A 5-year-old boy with Williams syndrome received open reduction of fracture of the antebrachium twice. He had been diagnosed as having Williams syndrome with some characteristic symptoms, including elfin face, mental retardation and primary pulmonary hypertension. Williams syndrome has a tetrad of cardiovascular disease, elfin face, mental retardation and hypercalcemia. Operations were performed twice under general anesthesia. Airway management with mask technique was easily performed. Tracheal intubation was accomplished successfully. Anesthesia was induced with propofol, fentanyl, and vecuronium, and maintained with propofol, fentanyl and the inhalation of oxygen with nitrous oxide. Both anesthetic courses were uneventful and he was discharged without any complications. Special anesthetic considerations should be taken for difficulties of intubation, management of circulatory system, malignant hyperthermia, and hypercalcemia in this syndrome.
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PMID:[Two occasions of anesthetic management for a patient with Williams syndrome]. 1367 82


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