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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A quite unique patient aged 13, characterized by a combination of organoid nevus on the left scalp and subtotal cerebellar agenesis accompanied by hypoplasia of the pons and midbrain, was reported. Cardinal clinical features consisted of nonprogressive cerebellar manifestations including intention tremor and ataxia, speech and visual disturbance and mental retardation. An electronystagmogram demonstrated periodic alternating nystagmus. A clinical diagnosis of cerebellar agenesis in this case was made through the demonstration of characteristic features in metrizamide CT and midline sagittal tomography of metrizamide cisternography of the posterior fossa. An extensive review of the literature revealed three papers dealing with organoid nevus associated with various neurological abnormalities, but no single case with a similar combination of cutaneous organoid nevus and cerebellar agenesis had been reported.
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PMID:An association of subtotal cerebellar agenesis with organoid nevus--a possible new variety of neurocutaneous syndrome. 666 Apr 24

Two female cases, 23- and 21-year-old, of supravalvular aortic stenosis associated with cerebellar hypoplasia, retinitis pigmentosa and myopathy were reported. No family history of mental retardation and cardiovascular anomalies was found. There was no consanguinity between the parents. Pregnancy, labor and delivery were reported to be uncomplicated. When they visited to our hospital at the age of 13 and 11 years, they had short stature, characteristic facial appearance (eg, wide mouth, elongated philtrum, low nasal bridge and broad forehead) and supravalvular aortic stenosis. Neurological examination disclosed mental retardation, retinitis pigmentosa, muscle wasting and contracture of bilateral knee and ankle joints. Gait was unsteady and bradykinetic. Their smooth pursuiting ocular movements were saccadic. No nystagmus was recorded. Mild intention tremor was present. The muscles were slightly hypotonic, but deep tendon reflexes were hyperactive in the lower extremities. The sensory system was normal. Results of chromosome analysis and urine amino acid analysis were normal. The serum creatine kinase was elevated to 1,000-3,000 U. Muscle biopsy revealed nonspecific myopathic changes such as variability of fiber diameter in both fiber types. Neither cell infiltration nor deposits of fat or glycogen was found. Cranial MRIs performed at the age of 22 and 20 years disclosed cerebellar hypoplasia and moderate enlargement of the fourth ventricle. The two cases resembled clinically those of Williams syndrome, but the MRI findings were not consistent with those of the syndrome. The disorder is considered to be either Williams syndrome complicated by some other relatively rare clinical features, or another heredofamilial disease partly resembling Williams syndrome.
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PMID:[Myopathy, cerebellar ataxia and Williams syndrome like features in siblings]. 819 69

The FMR1 gene is involved in two different syndromes: Fragile X syndrome and Fragile X-associated tremor/ataxia syndrome (FXTAS). Fragile X syndrome is a childhood disease and is associated with mental retardation as the main clinical characteristic, whereas FXTAS develops in men and women over 50 years of age. FXTAS represents a new form of inclusion disorder with a high prevalence in the general population. The neurologic phenotype of FXTAS includes intention tremor and ataxia. Associated features are dementia, parkinsonism, neuropathy, and autonomic dysfunction. Elevated FMR1 transcripts have been proposed as the molecular basis of the pathogenic mechanism leading to FXTAS. This review discusses recent developments in the clinical phenotype, prevalence and screening, animal models, and molecular mechanisms of RNA-based pathogenesis in FXTAS.
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PMID:FXTAS: a progressive neurologic syndrome associated with Fragile X premutation. 1613 24

We have identified three truncating, two splice-site, and three missense variants at conserved amino acids in the CUL4B gene on Xq24 in 8 of 250 families with X-linked mental retardation (XLMR). During affected subjects' adolescence, a syndrome emerged with delayed puberty, hypogonadism, relative macrocephaly, moderate short stature, central obesity, unprovoked aggressive outbursts, fine intention tremor, pes cavus, and abnormalities of the toes. This syndrome was first described by Cazebas et al., in a family that was included in our study and that carried a CUL4B missense variant. CUL4B is a ubiquitin E3 ligase subunit implicated in the regulation of several biological processes, and CUL4B is the first XLMR gene that encodes an E3 ubiquitin ligase. The relatively high frequency of CUL4B mutations in this series indicates that it is one of the most commonly mutated genes underlying XLMR and suggests that its introduction into clinical diagnostics should be a high priority.
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PMID:Mutations in CUL4B, which encodes a ubiquitin E3 ligase subunit, cause an X-linked mental retardation syndrome associated with aggressive outbursts, seizures, relative macrocephaly, central obesity, hypogonadism, pes cavus, and tremor. 1723 39

This article attempts to describe a very unusual case of a boy aged 15, who has had intractable epileptic phenomena, mental retardation, megalocephaly, micrognathy, syndactyly, small tongue, hypoplastic genitalia, gynecomasty, obesity, and slight left body hemiatrophy. Neurologically the patient has had hypotonia of the lower limbs, cerebellar dysfunction including horizontal nystagmus, bilateral intention tremor, dysdiadokokinesia, gait ataxia. The clinical investigation revealed low plasma cholesterol and hypoplasia of the vermis in MRI. The epileptic phenomena were intractable and polymorphous. One should have thought that this is an unusual case of Smith-Lemli-Opitz syndrome associated with features of Joubert syndrome.
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PMID:Clinical case: vermis hypoplasia with features of Smith-Lemli-Opitz syndrome. 1736 27

Few women with Fragile X tremor ataxia syndrome (FXTAS) have been reported. They have milder manifestations at a later age than men. This gender difference may be related to the X inactivation pattern in women. We describe a woman who presented to her geriatrician with poor memory and was found to have ataxia and tremor. Additional queries yielded history of premature ovarian failure. Genetic testing showed heterozygous fragile X mental retardation gene premutation with 103 CGG repeats in the abnormal allele and 31 CGG repeats in the normal allele. Also, the X inactivation pattern was skewed with the active X chromosome predominantly having the premutation allele. We believe that FXTAS is more common in women than is generally thought and that many such patients masquerade as dementia of old age. Action tremor and ataxia associated with a history suggestive of premature ovarian failure should raise suspicions for FXTAS.
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PMID:Fragile X premutation in a woman with cognitive impairment, tremor, and history of premature ovarian failure. 1780 60

Cabezas syndrome (MIM 300354) is a recently identified syndromic form of X-linked mental retardation (XLMR) caused by mutations in the CUL4B gene. In total, nine XLMR families carrying mutations in the CUL4B gene have been described to date. Here, we present a detailed clinical phenotype of three affected brothers of Polish descent. Based on the symptoms, we made a clinical diagnosis of Cabezas syndrome, which was subsequently confirmed by identification of a novel nonsense mutation (c.2107A-->T, p.703K-->X) in exon 18 of the CUL4B gene. The mutation was inherited from an asymptomatic mother and was present in all three affected brothers. The patients presented with typical features of Cabezas syndrome, such as severe mental retardation, speech impairment, hyperactivity, seizures, intention tremor, inguinal hernia, small feet, and craniofacial dysmorphism. In addition to previously described symptoms, syndactyly of the second and third toes and skin manifestations (hyperhydrosis and keratosis pilaris) were present in our cases. Our report provides further support that Cabezas syndrome is a recognizable syndromic form of XLMR. We conclude that the CUL4B gene should be screened in males with severe speech impairment and primary intention tremor, especially if characteristic facial dysmorphism is also present.
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PMID:A novel nonsense mutation in CUL4B gene in three brothers with X-linked mental retardation syndrome. 2000 52

A 71-year-old man developed postural tremor and was treated as an essential tremor patient. Nine years after the tremor onset, he developed symptoms resembling Fragile-X-associated tremor/ataxia syndrome (FXTAS), including exacerbated (increased coarseness and amplitude) tremor in the right arm, ataxic gait, and brain MRI showed lesions in the bilateral middle cerebellar peduncles (MCP). Evidence of premutation in the form of 83 CGG repeats of the Fragile-X-mental retardation 1 (FMR1) gene confirmed the diagnosis of FXTAS. FXTAS causes various neurological symptoms including in some cases tremor resembling essential tremor in the early stages. FMR1 gene premutation should be checked when the patient develops intention tremor, cerebral dysfunction and/or a brain MRI shows MCP lesions.
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PMID:A Japanese case of fragile-X-associated tremor/ataxia syndrome (FXTAS). 2055 44

FXTAS (Fragile X-associated tremor and ataxia syndrome) is a late- onset neurodegenerative disorder affecting mainly men, over 50 years of age, who are carriers of the FMR1 gene premutation. The full mutation of this gene causes the fragile X syndrome (FXS), the most common cause of inherited mental retardation. Individuals affected by FXTAS generally present intention tremor and gait ataxia that might be associated to specific radiological and/or neuropathological signs. Other features commonly observed are parkinsonism, cognitive decline, peripheral neuropathy and autonomic dysfunction. Nearly a decade after its clinical characterization, FXTAS is poorly recognized in Brazil. Here we present a review of the current knowledge on the clinical, genetic and diagnostic aspects of the disease.
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PMID:The fragile x-associated tremor and ataxia syndrome (FXTAS). 2104 96

Fragile X-associated tremor/ataxia syndrome is a neurodegenerative disorder that primarily affects older male premutation carriers of the fragile X mental retardation gene. Although its core symptoms are mainly characterized by motor problems such as intention tremor and gait ataxia, cognitive decline and psychiatric problems are also commonly observed. Past radiological and histological approaches have focused on prominent neurodegenerative changes in specific brain structures including the cerebellum and limbic areas. However, quantitative investigations of the regional structural abnormalities have not been performed over the whole brain. In this study, we adopted the voxel-based morphometry method together with regions of interest analysis for the cerebellum to examine the pattern of regional grey matter change in the male premutation carriers with and without fragile X-associated tremor/ataxia syndrome. In a comparison with healthy controls, we found striking grey matter loss of the patients with fragile X-associated tremor/ataxia syndrome in multiple regions over the cortical and subcortical structures. In the cerebellum, the anterior lobe and the superior posterior lobe were profoundly reduced in both vermis and hemispheres. In the cerebral cortex, clusters of highly significant grey matter reduction were found in the extended areas in the medial surface of the brain, including the dorsomedial prefrontal cortex, anterior cingulate cortex and precuneus. The other prominent grey matter loss was found in the lateral prefrontal cortex, orbitofrontal cortex, amygdala and insula. Although the voxel-wise comparison between the asymptomatic premutation group and healthy controls did not reach significant difference, a regions of interest analysis revealed significant grey matter reduction in anterior subregions of the cerebellar vermis and hemisphere in the asymptomatic premutation group. Correlation analyses using behavioural scales of the premutation groups showed significant associations between grey matter loss in the left amygdala and increased levels of obsessive-compulsiveness and depression, and between decreased grey matter in the left inferior frontal cortex and anterior cingulate cortex and poor working memory performance. Furthermore, regression analyses revealed a significant negative effect of CGG repeat size on grey matter density in the dorsomedial frontal regions. A significant negative correlation with the clinical scale for the severity of fragile X-associated tremor/ataxia syndrome was found in a part of the vermis. These observations reveal the anatomical patterns of the neurodegenerative process that underlie the motor, cognitive and psychiatric problems of fragile X-associated tremor/ataxia syndrome, together with incipient structural abnormalities that may occur before the clinical onset of this disease.
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PMID:A voxel-based morphometry study of grey matter loss in fragile X-associated tremor/ataxia syndrome. 2135 78


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