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)

Comparison of the properties of blood platelets and serotonergic synaptosomes suggests that the human platelet can serve as an appropriate model for the transport, metabolism, and release of serotonin (5-HT) by CNS serotonergic neurons. The study of blood 5-HT levels and platelet 5-HT pharmacodynamics in patients with a variety of psychiatric and neurologic disorders has generated interesting leads into possible abnormalities of CNS 5-HT neurons in these patients. This article reviews the experimental evidence, which uses the human platelet model to investigate neurotransmitter-related abnormalities in Down syndrome, mental retardation, infantile autism, hyperactivity syndromes (minimal brain dysfunction), schizophrenia, affective disorders, Duchenne muscular dystrophy, Parkinson disease, Huntington chorea, and migraine headaches.
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PMID:The human platelet. A diagnostic and research tool for the study of biogenic amines in psychiatric and neurologic disorders. 14 Jun 32

Glutaric aciduria is a disorcer of lysine, tryptophan, and hydroxylysine metabolism characterized by intermittent metabolic acidemia, dystonia, athetosis and mental retardation. It is due to a recessively inherited deficiency of glutaryl-CoA dehydrogeanse, the enzyme(s) which catalyze the dehydrogenation of glutaryl-CoA to glutaconyl-CoA and decarboxylation of the latter to crotonyl-CoA. Abnormal quantities of glutaric, beta-hydroxyglutaric, and glutaconic acids are found in the urine of these patients. The nature of the movement disorder prompted study of the effects of the abnormally excreted metabolites on brain glutamate decarboxylase, an enzyme implicated in the pathogenesis of Huntington's chorea. Glutamate decarboxylase activity was examined in rat and rabbit brain acetone powders, stabilized with pyridoxal phosphate and glutathione. Glutarate, beta-hydroxyglutarate, and glutaconate were competitive inhibitors of this emzyme, Ki values being 1.3 X 10(-3) mol/l, 2.5 X 10(-4) mol/l, respectively. This inhibition may explain the neurological accompaniments of this syndrome.
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PMID:Inhibition of brain glutamate decarboxylase by glutarate, glutaconate, and beta-hydroxyglutarate: explanation of the symptoms in glutaric aciduria? 124 44

Increasingly, human genes are being identified by the "reverse genetics", or "positional cloning" approach. This molecular genetic strategy is particularly useful in mental illness, for which no readily detectable functional alterations are present to indicate candidate genes. The positional cloning procedure is briefly described. Significant examples of successful positional cloning are presented, including the fragile-X mental retardation syndrome gene. The study of gene expression may be complicated by genetic and non-genetic variability. Genomic imprinting may play a role in several mental illnesses, and may provide an explanation for the unusual inheritance pattern in fragile-X syndrome, for the phenotypic differences observed between Angelman and Prader-Willi syndromes, and for the juvenile onset form of Huntington disease. DNA instability may explain disease anticipation in fragile-X syndrome and myotonic dystrophy. Finally, the prospects of improvements in positional cloning methods for tracking genes responsible for mental illness are briefly discussed.
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PMID:Tracking disease genes by reverse genetics. 149 55

Perinatal cerebral asphyxia, which results in significant neurologic and cognitive disabilities in infants and children, remains a major health problem. Potential neurologic sequelae include cerebral palsy, mental retardation, and epilepsy. Over the next few years, neuroprotective agents that prevent asphyxial neuronal injury and death are likely to be developed. These agents may also be effective in prophylaxis and treatment of chronic neurologic disorders, including epilepsy and neurodegenerative disorders, such as Huntington disease.
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PMID:Results of N-methyl-D-aspartate antagonists in perinatal cerebral asphyxia therapy. 198 66

Using Huntington disease, mental retardation, and schizophrenia, it has been shown that two individuals with identical genotypes or phenotypes have different fitnesses because of affected nuclear family members. Such fitness interaction seems to occur because of cultural and social reactions due to the presence of affected individuals, and the interaction has been termed "social selection." Without assuming any specific genetic control for the social behavior, we can study the effect of social behavior on the incidence of a genetic disease.
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PMID:Theories of social selection in human populations. 622 46

A unique case of Huntington's disease is reported because of the extremely early onset and death, and the atypical mode of presentation including severe behavioural problems and a negative family history. Although rare, Huntington's disease must be considered along with the established degenerative disorders of white and gray matter peculiar to the pediatric population when one examines an infant or child with progressive motor deterioration, rigidity, mental retardation and behavioural abnormalities. Computed tomography is a reliable and non-invasive method of establishing the diagnosis during life.
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PMID:Infantile Huntington's disease. 622 2

Disease incidences in human populations depend on etiology of the disease, the fitness of individuals, and demographic changes of the population. The fitness of an individual is determined not only by the disease but also by other factors such as cultural and social reaction to the disorder and demographic changes of the population. Social selection studies the effect of the social behavior on the incidence of a trait. In studies of Huntington's disease, it has been shown that the fitness of the normal sibling of an affected individual is reduced as much as that of the affected individual himself or herself. A similar social effect has been observed for mental retardation. Thus, even if an individual has a normal genotype, mate finding and fertility may be changed considerably by the presence of affected family members. At the present time, the way in which genetic variabilities are maintained is poorly understood even for clearcut genetic diseases. Studies of social selection indicate that such information should be acquired by considering both the nature of the disease and its social effect.
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PMID:Social selection and evolution of human diseases. 622 4

The authors describe a man aged 22 years with signs of parkinsonian syndrome and evidence of slight mental retardation besides an evident hereditary background of Huntington's chorea.
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PMID:[Case of juvenile form of Huntington chorea]. 644 89

Herein we describe the molecular and clinical findings in a North American Caucasian family with dentatorubral-pallidoluysian atrophy (DRPLA). These patients all presented with an autosomal dominant neurodegenerative disorder characterized by a variable combination of clinical symptoms including seizures, ataxia, dementia, choreiform movements, mental retardation, and psychiatric disease. Neuroradiologic findings in the index case revealed deep subcortical white matter changes on magnetic resonance imaging. Prior to referral, the family carried a diagnosis of Huntington's disease (HD). Subsequent direct molecular testing for HD failed to identify the HD expansion mutation in affected individuals. Molecular testing for DRPLA, however, demonstrated the presence of the recently characterized DRPLA expansion mutation in all affected individuals. The size of the expansion correlated with the age of onset of clinical symptoms. As DRPLA has rarely been reported in North American and European populations, the molecular confirmation of DRPLA in this family provides support for the hypothesis that DRPLA may not be as geographically restricted as once thought.
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PMID:Molecular and clinical findings in a family with dentatorubral-pallidoluysian atrophy. 784 69

Over the past few years, molecular neurogenetics has developed into one of the most promising and active research fields. The new discipline applies modern molecular genetic techniques to the investigation of classical neurological disorders. In the following article, a definition of neurogenetic disease is introduced, the molecular basis of four groups of neurogenetic disorders is described and recent diagnostic developments are presented. The first group of diseases is caused by trinucleotide expansions. "Expanding" trinucleotide repeats were not known to occur in any species until about three years ago. Today, disorders such as Huntington's disease, spinocerebellar ataxia type 1, fragile X mental retardation, spinobulbar muscular atrophy and myotonic dystrophy are all known to be caused by the expansion of trinucleotides. The second group is characterized by chromosomal deletions or uniparental disomies. Lissencephaly and the Miller-Dieker syndrome, Prader-Willi and Angelman syndromes and Duchenne and Becker muscular dystrophies belong to this category. The third group includes those neurogenetic disorders that are mainly caused by point mutations such as the X-linked leukodystrophies, including Pelizaeus-Merzbacher disease and adrenoleukodystrophy, Charcot-Marie-Tooth syndrome type 1, familial forms of amyotrophic lateral sclerosis, several types of craniosynostoses and some CNS tumor syndromes. Finally, Alzheimer's and Parkinson's disease are discussed as representatives of group four, i.e. genetically heterogeneous neurological disorders.
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PMID:Molecular basis and diagnosis of neurogenetic disorders. 796 63


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