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)

Hallervorden-Spatz disease is a rare, autosomal-recessive hereditary condition characterized by early onset of progressive movement alterations such as dystonia, rigidity, and choreoathetosis, which is usually associated with pyramidal signs and mental deterioration. The authors report two cases for which diagnosis of Hallervorden-Spatz disease was based on clinical manifestations that appeared during the first year of life, illness progression, and late-stage magnetic resonance imaging findings. The possibility that these two cases, along with other previously described rare instances with similar clinical features, be considered as a variant of subtype of the early-onset type of Hallervorden-Spatz disease is suggested. The need to differentiate these cases from cases of static encephalopathy with mental retardation and motor impairment is also stressed.
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PMID:Hallervorden-Spatz disease: two new early childhood onset cases. 1064 7

Primary dystonias are movement disorders with dystonia as a major symptom. They are frequently inherited as Mendelian traits. There are at least eight clinically distinct autosomal dominant and two X-linked recessive forms. In addition, pedigree analyses suggest the occurrence of an autosomal recessive variant. The clinical classification is increasingly being replaced by a genetic one. To date gene loci have been identified in at least six autosomal dominant forms, i.e., in idiopathic torsion dystonia (9q34), focal dystonia (18p), adult-onset idiopathic torsion dystonia of mixed type (8p21-q22), dopa-responsive dystonia (14q22.1-q22.2), and paroxysmal dystonic choreoathetosis (2q25-q33; 1p21-p13.3). Gene loci in the X-linked recessive forms have been assigned to Xq13.1 in the X-linked dystonia parkinsonism syndrome and to Xq22 in X-linked sensorineural deafness, dystonia, and mental retardation. The disease genes have been identified in two autosomal dominant forms and in one X-linked recessive form. Mutations in a gene coding for an ATP-binding protein were detected in idiopathic torsion dystonia (DYT1), and the GTP cyclohydrolase 1 gene is mutated in dopa-responsive dystonia (DYT5). In sensorineural deafness, dystonia, and mental retardation, mutations were found in the gene DDP coding for a polypeptide of unknown function. This article reviews the clinical and molecular genetics of primary dystonias, critically discusses present findings, and proposes referring to the known forms, most of which can be distinguished by genetic criteria, as dystonias 1-12.
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PMID:Clinical and molecular genetics of primary dystonias. 1073 19

18p- syndrome from chromosomal deletion of the short arm of chromosome 18 shows a wide range of clinical manifestations. Mental retardation is the most frequent neurological complication; other neurological deficits are more rarely reported. Only one 18p- patient with focal dystonia at the lower limbs has been reported, while there have been no reported cases of generalized dystonia. We report a 27-year-old male with 18p- de novo complete deletion (karyotype 46,XY,18p-) who was affected by severe generalized dystonia, hypokinesia, mental retardation and dysmorphic features. The 18p- syndrome should be added to the list of genetic causes of secondary dystonia. A karyotype analysis should be considered in secondary dystonias, particularly when there are associated dysmorphic features and mental retardation.
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PMID:Dystonia in a patient with deletion of 18p. 1093 43

There is a now a substantial body of evidence that suggests the new antipsychotic agent, risperidone, may be safe and effective for treating psychotic, affective or behavioural symptoms associated with various disorders other than schizophrenia, schizophreniform disorder or schizo-affective disorder. These conditions include bipolar disorder, obsessive-compulsive disorder, Tourette's syndrome, dementia, Lewy body disease, mental retardation, Parkinson's disease, idiopathic segmental dystonia and organic catatonia. Although much of the data is anecdotal or in the form of open studies, there is now emerging a small number of well controlled investigations supporting efficacy for mania, dementia, behavioural disturbance in mental retardation and conduct disorder. Conventional antipsychotics have long been used, either in a primary capacity or as an adjunct to treat these disorders; however, they have limited benefit, pose significant risks of extrapyramidal side-effects, and may cause the potentially life-threatening neuroleptic malignant syndrome. In contrast, risperidone at the recommended low doses may be efficacious and pose reduced risk of motor side-effects. This article reviews the evidence that risperidone may be an effective new treatment for disorders other than schizophrenia.
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PMID:Does risperidone have a place in the treatment of nonschizophrenic patients? 1119 55

Hearing loss in patients with X-linked agammaglobulinemia is often attributed to recurrent infections. However, recent genetic studies suggest a different etiology in some patients. We present three unrelated patients, 6, 9, and 14 years of age, with large deletions of the terminal portion of the Bruton tyrosine kinase (Btk) gene extending 4.2-19 kb beyond the 3' end of the gene. The DNA immediately downstream of the 3' end of Btk contains the deafness-dystonia protein gene (DDP). Mutations in this gene have recently been shown to underlie the Mohr-Tranebjaerg syndrome, which is characterized by sensorineural deafness, dystonia, and mental deficiency. Besides the immunodeficiency, our patients exhibited progressive sensorineural deafness. The clue to an associated hearing problem was delayed development of speech in one patient and post-lingual deafness noticed between the age of 3-4 years in the other two. These patients have not yet exhibited significant associated neurologic deficits.
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PMID:A contiguous deletion syndrome of X-linked agammaglobulinemia and sensorineural deafness. 1133 84

Mental retardation and epilepsy often occur together. They are both heterogeneous conditions with acquired and genetic causes. Where causes are primarily genetic, major advances have been made in unraveling their molecular basis. The human X chromosome alone is estimated to harbor more than 100 genes that, when mutated, cause mental retardation. At least eight autosomal genes involved in idiopathic epilepsy have been identified, and many more have been implicated in conditions where epilepsy is a feature. We have identified mutations in an X chromosome-linked, Aristaless-related, homeobox gene (ARX), in nine families with mental retardation (syndromic and nonspecific), various forms of epilepsy, including infantile spasms and myoclonic seizures, and dystonia. Two recurrent mutations, present in seven families, result in expansion of polyalanine tracts of the ARX protein. These probably cause protein aggregation, similar to other polyalanine and polyglutamine disorders. In addition, we have identified a missense mutation within the ARX homeodomain and a truncation mutation. Thus, it would seem that mutation of ARX is a major contributor to X-linked mental retardation and epilepsy.
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PMID:Mutations in the human ortholog of Aristaless cause X-linked mental retardation and epilepsy. 1188 67

We reported three siblings with complicated hereditary spastic paraplegia. The striking features in these patients were characterized by early onset of gait disturbance, mental deficiency, and dystonia. The most likely diagnosis was Mast syndrome. Patient 1: A 44 years-old woman. She first developed gait disturbances at age of 8. She was admitted in our hospital because of progressive spastic paraplegia. Neurological examination revealed mental deficiency, saccadic pursuit eye movement, speech disturbance of cerebellar type, ataxia, and spastic paraplegia. She showed also dystonia in the face, tongue, and trunk. MRI showed cerebellar atrophy. Patient 2: A 51 years-old brother of the patient 1. He had mentally retarded. Late teens he developed gait disturbance. Gradually he manifested spastic paraplegia, dysarthria, dysphasia, mental deficiency, and ataxia. He also showed incontinence of urine and feces. Then he became bedridden, apathetic, and showed forced crying. MRI showed diffuse brain atrophy. Patient 3: A 48 year-old woman. This woman, a sister of the patient 1, showed progressive gait disturbance and dysarthria. She also developed incontinence, apathy, and dystonia. She became bedridden, responding to simple questions with only occasional single-word answers. Her speech was slurred, and spastic paraplegia was noted. MRI showed diffuse brain atrophy including marked atrophy of the cerebellum.
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PMID:[A family of hereditary spastic paraplegia with dementia, ataxia, and dystonia]. 1199 89

Partington et al. [1988] described a three-generation family (MRXS1, MIM *309510, PRTS) with a syndromic form of X-linked mental retardation (XLMR). The clinical features in 10 affected males included mild to moderate MR, dystonic movements of the hands, and dysarthria. After refinement, the PRTS locus was mapped to marker DXS989 (with maximum LOD score of 3.1) with flanking markers DXS365 and DXS28. Since then, no other patients with a similar phenotype have been described. We present a detailed description of the neurological symptoms and the disease history of two brothers with the clinical features of PRTS. Psychomotor development was delayed in both, and neurological features included mild to moderate mental retardation, dysarthria, facial muscle weakness, severe dysdiadochokinesis, slow dystonic movements, and mild spasticity of the hands, without ataxia or spasticity of the legs. The symptoms were nonprogressive and extrapyramidal, and without cerebellar involvement. In general, behavior of the two brothers was friendly and quiet, although the elder brother had periods of depressed mood and outbursts of anger. Karyotypes and subsequent investigation of the subtelomeres as well as DNA analysis of the FMR1 gene, the androgen receptor gene, and the DM locus did not reveal a genetic abnormality. Haplotype analysis showed that the affected brothers share the PRTS region at Xp22.1. Mutation screening of the PDH-E1alpha gene did not reveal a pathogenic mutation.
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PMID:Clinical study and haplotype analysis in two brothers with Partington syndrome. 1237 38

Two families, originally diagnosed as having nonsyndromic X-linked mental retardation (NSXLMR), were reviewed when it was shown that they had a 24-bp duplication (428-45 1dup(24bp)) in the ARX gene [Stromme et al., 2002: Nat Genet 30:441-445]. This same duplication had also been found in three other families: one with X-linked infantile spasms and hypsarrhythmia (X-linked West syndrome, MIM 308350) and two with XLMR and dystonic movements of the hands (Partington syndrome, MIM 309510). On review, manifestations of both West and Partington syndromes were found in some individuals from both families. In addition, it was found that one individual had autism and two had autistic behavior, one of whom had epilepsy. The degree of mental retardation ranged from mild to severe. A GCG trinucleotide expansion (GCG)10+7 and a deletion of 1,517 bp in the ARX gene have also been found in association with the West syndrome, and a missense mutation (1058C>T) in a family with a newly recognized form of myoclonic epilepsy, severe mental retardation, and spastic paraplegia [Scheffer et al., 2002: Neurology, in press]. Evidently all these disorders are expressions of mutations in the same gene. It remains to be seen what proportions of patients with infantile spasms, focal dystonia, autism, epilepsy, and nonsyndromic mental retardation are accounted for by mutations in the ARX gene.
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PMID:Variable expression of mental retardation, autism, seizures, and dystonic hand movements in two families with an identical ARX gene mutation. 1237 46

Inherited metabolic disorders can cause onset of epilepsy in the first year of life. Epilepsy rarely dominates the clinical presentation, which is more frequently associated with other neurologic symptoms, such as mental retardation, hypotonia and/or dystonia, or vigilance disturbances. The pathogenesis of seizures is multifaceted; inherited metabolic disorder can affect the balance between excitatory and inhibitory chemical mediators, eliminate an energetic substrate at the cerebral level, cause in utero brain malformation, or provoke acute brain lesions. Some clinical disorders that strongly suggest particular metabolic etiologies can be identified. For example, specific clinical signs and findings on electroencephalogram (EEG) are characteristic of pyridoxine-dependent seizures, and inherited metabolic disorders associated with early myoclonic encephalopathy are well defined. In most cases, however, epilepsy secondary to inherited metabolic disorders presents with polymorphic clinical and EEG features that are difficult to classify into precise epileptic syndromes. Common characteristics of these seizures include onset in the first months of life; usually partial, multifocal; simple partial motor semiology; successive appearance of tonic seizures, spasms, and massive myoclonus; and resistance to antiepilepsy drugs. Inherited metabolic disorders must be considered in patients presenting with epilepsy and progressive neurologic worsening.
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PMID:Infantile epileptic syndromes and metabolic etiologies. 1259 51


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