Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917816 (mental retardation)
 15,867 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

X-linked hydrocephalus-stenosis of the aqueduct of Sylvius sequence (H-SAS, MIM number 307,000) is a rare genetic disorder characterized by hydrocephalus, macrocephaly, adducted thumbs, spasticity, mental retardation, and cerebral malformations. This regularly lethal condition is usually diagnosed at birth or prenatally by ultrasound, but hydrocephalus may be moderate or even undetectable on fetal ultrasound examination. Moreover, since heterozygous women are asymptomatic, carrier detection is at present impossible before the birth of an affected son. Therefore, mapping the H-SAS locus to distal Xq (Xq28) was of primary importance for genetic counselling and prenatal diagnosis. Here, we report prenatal exclusion of H-SAS with a probability of 97.6 per cent in two male fetuses with a 50 per cent a priori risk of being affected using closely linked Xq28 DNA markers.
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PMID:Prenatal exclusion of X-linked hydrocephalus-stenosis of the aqueduct of Sylvius sequence using closely linked DNA markers. 837 68

Prolidase deficiency is a rare hereditary disorder with a wide spectrum of clinical manifestations including skin ulcers, eczematous eruptions, characteristic facies, mental retardation, splenomegaly, and susceptibility to infections. We report two new cases of prolidase deficiency. Our patients had the typical manifestations of prolidase deficiency. One also had lupus erythematosus. Prolidase activity was either normal or half-normal in all family members. The skin disease in our patients did not respond to topical glycine/proline ointment or to oral vitamin C.
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PMID:Prolidase deficiency: a multisystemic hereditary disorder. 840 17

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder primarily affecting young boys, often causing mental retardation in addition to the well-known progressive muscular weakness. Normal dystrophin expression is lacking in skeletal muscle and the CNS of both DMD children and the mdx mouse model. To date, 31P-magnetic resonance spectroscopy (MRS) has shown in vivo several abnormalities within skeletal muscle of mdx mice and DMD boys. In this study, we determined whether similar abnormalities occur in mdx brain in vivo by using 31P-MRS in addition to metabolite and enzyme analysis to study cerebral metabolism. An increased inorganic phosphate (P(i))/phosphocreatine (PCr) and pH was found in vivo for mdx brain compared with controls, and biochemical analysis showed a reduction in total creatine, an increased extracellular and decreased intracellular volume in mdx brain. No differences were found in any glycolytic or mitochondrial maximal enzyme activities. These changes are discussed with respect to the biochemical changes found in muscle from DMD patients and mdx mice. It is proposed that these biochemical changes may be a factor in the reduced cognitive capacity of mdx mice and some DMD children.
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PMID:Brain metabolism is abnormal in the mdx model of Duchenne muscular dystrophy. 867 81

Seckel syndrome is a clinical picture which associates four main features: intrauterine growth retardation, microcephaly often due to craniosynostosis, orofacial dysmorphology with bird headed appearance and variable mental retardation which is present after several months. Malformations of the central nervous system, limbs, and hair, may also be observed. On the basis of 78 cases reported in the literature, the authors discuss the validity of the morphological features of the syndrome. It is likely that the variability in the expressivity of each symptom explains its heterogeneity. According to the radiological abnormalities, three different forms of the syndrome have been described. Seckel syndrome is a genetic disorder with autosomal recessive inheritance. Its ethiopatogeny remains unclear. Hopefully linkage studies will allow to map the gene in order to determine the underlying abnormal protein.
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PMID:[Bird headed dwarfism in Seckel syndrome. Nosologic difficulties]. 874 29

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder primarily affecting young boys, often causing mental retardation in addition to the well-known progressive muscular weakness. Normal dystrophin expression is lacking in skeletal muscle and the central nervous system (CNS) of both DMD children and the mdx mouse model. The underlying biochemical lesion causing mental impairment in DMD is unknown. 1H-magnetic resonance spectroscopy (1H-MRS) detects choline-containing compounds, creatine and N-acetyl aspartate (NAA) in vivo. NAA is commonly used as a chemical marker for neurons, and a decline in NAA is thought to correlate with neuronal loss. Control mice were compared to mdx using a combination of in vivo and in vitro 1H-MRS methods to determine whether neural necrosis or developmental abnormalities occur in dystrophic brain. NAA levels were normal in mdx brain compared to controls suggesting minor, if any, neuronal necrosis in dystrophic brain. In contrast, choline compounds and myo-inositol levels were increased, indicative of gliosis or developmental abnormalities in dystrophic brain.
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PMID:An in vivo and in vitro H-magnetic resonance spectroscopy study of mdx mouse brain: abnormal development or neural necrosis? 888 Jun 86

Dyskeratosis congenita (DC), or the Zinsser-Engman-Cole syndrome, is a rare X-linked heritable disorder, affecting primarily the ectodermal tissues, with hyperpigmentation of the skin, leukoplakia of the buccal and anal mucosa, and nail dystrophy (1, 2). Aplastic anemia (3) and a variety of neoplasms (4, 5) are some of the extraectodermal manifestation of this disorder, which although X-linked recessive, has also been described in a few females (6, 7). Mental retardation, diarrhea, and gastrointestinal bleeding have been considered to be less frequent features (8). We report an adolescent Indian male who presented with all the ectodermal manifestations, as well as mental retardation, bone marrow aplasia, and gastrointestinal hemorrhage secondary to adenocarcinoma of the stomach.
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PMID:Case report: gastric carcinoma as a complication of dyskeratosis congenita in an adolescent boy. 901 39

We present a family with congenital cataract with, in some cases, mental retardation and emotional instability, but intellectual deterioration in all affected members. The latter was accompanied by psychosis in some. The inheritance is most likely autosomal dominant, affecting two generations and consisting of a congenitally blind parent and 6 of 11 of her offspring. In addition to these features, some affected individuals had dysphagia and movement disorder, especially choreiform movements. They all showed small body mass, due possibly to poor nutrition from dysphagia. The pathological findings were unique, demonstrating selective atrophy of the granule cell layer of the dentate gyrus. There was selective expression in paraffin-embedded sections of alpha B-crystallin (CRYA2) in oligodendroglia in all areas of the nervous system examined. alpha B-Crystallin is a major optic lens protein but also a heat shock protein and molecular chaperone found in brain and a number of other tissues. Because of the association of congenital cataract and the accumulation in oligodendroglia of alpha B-crystallin, the gene for this protein was sequenced for possible mutation. No mutation was found indicating other genetic locus. This family appears to have a newly recognized genetic disorder.
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PMID:A familial syndrome of congenital cataract, mental impairment, and dentate gyrus atrophy. 912 9

Radiographic periodontal status and microbiological findings of periodontal pockets in subjects with Cohen syndrome are presented in this report. This hereditary disorder causes mental retardation, and neutropenia is one feature of the syndrome. Fifteen patients with Cohen syndrome and 15 controls matched for age and sex and, as far as possible, according to the degree of mental retardation were examined. Alveolar bone loss was evaluated from the panoramic radiographs. Two subgingival samples were obtained from the most affected anterior and posterior periodontal sites in each dentate subject and examined for the occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Peptostreptococcus micros, Bacteroides forsythus, and Campylobacter rectus. Subjects with Cohen syndrome had alveolar bone loss more frequently and the bone loss was more extensive (Mann-Whitney U-test: P < 0.05) than in the controls. They also harbored one or several of the putative periodontal pathogens (Mann-Whitney U-test: P < 0.001) more often than the controls. We conclude that subjects with Cohen syndrome have increased susceptibility to early periodontal breakdown which is likely to be associated with neutropenia.
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PMID:Periodontal findings in Cohen syndrome with chronic neutropenia. 918 43

Direct and indirect behavioral effects of genetic disorders of mental retardation were identified. Three models of direct effects were examined: the no-specific effect model (all genetic disorders lead to identical behavioral outcomes), the totally specific model (each genetic disorder leads to unique outcomes), and the partially specific model (two or more genetic disorders lead to outcomes not shared by others with mental retardation). Although several cases of totally specific outcomes have been identified, partially specific effects most often occur. Persons in the surrounding environment are indirectly affected by behavioral propensities of different genetic disorders. Direct and indirect effects are also related to biological and developmental theory.
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PMID:Direct and indirect behavioral effects of different genetic disorders of mental retardation. 924 9

The amino acid proline has long been suspected to serve as a modulator of synaptic transmission in the mammalian brain, but no such function has been identified. The selective expression of high affinity proline transport by a subset of glutamate pathways suggested that proline might play a role in synaptic transmission at these sites. This idea was tested with use of one such pathway, the Schaffer collateral-commissural projection to CA1 pyramidal cells of the rat hippocampus. Proline enhanced the initial slope of the field EPSP without affecting axonal excitability or the magnitude of paired-pulse facilitation. Proline-induced potentiation far outlasted the period of proline application and required the activation of NMDA receptors. Proline enhanced Schaffer collateral-commissural synaptic transmission even when the connections between areas CA1 and CA3 had been interrupted. Potentiation was observed with a proline concentration normally present in human CSF (3 microM). A concentration typical of CSF in persons with the genetic disorder hyperprolinemia type II (30 microM) produced a somewhat greater effect. Occlusion experiments suggested that proline-induced potentiation and tetanus-induced long-term potentiation utilize largely distinct transduction mechanisms. Proline-induced potentiation could be blocked by a prior high frequency stimulus, whether or not the stimulus evoked long-term potentiation. These results suggest that endogenous extracellular proline regulates the basal function of some glutamate synapses by maintaining them in a partially potentiated state. They may also facilitate understanding of the seizures and/or mental retardation associated with genetic disorders of proline metabolism.
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PMID:Proline-induced potentiation of glutamate transmission. 925 26


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