Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Angelman syndrome (AS) is a neurological disorder characterized by severe mental retardation, absent speech, seizures, gait disturbances, and a typical age-dependent facial phenotype. Most cases are due to an interstitial deletion on the maternally inherited chromosome 15, in the critical region q11-q13. Rare cases also result from paternal uniparental disomy of chromosome 15. In a group of 14 patients with sporadic AS diagnosed in Switzerland, we found 2 unrelated females with paternal isodisomy for the entire chromosome 15. Their phenotypes were milder than usually seen in this syndrome: one girl did not show the typical AS facial changes; both patients had late-onset mild seizures; as they grew older, they had largely undisturbed gross motor functions, in particular no severe ataxia. Both girls were born to older fathers (45 and 43 years old, respectively). The apparent association of a relatively milder phenotype in AS with paternal uniparental disomy will have to be confirmed by detailed clinical descriptions of further patients.
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PMID:Angelman syndrome due to paternal uniparental disomy of chromosome 15: a milder phenotype? 777 2

Carbohydrate-deficient glycoprotein syndrome is characterized by mental retardation, ataxia, hepatopathy during infancy, cerebellar hypoplasia, peripheral neuropathy, internal strabismus, growth retardation and stroke-like episodes. Since the description of female siblings with unique clinical and biochemical features by Jaeken (1980) and the discovery of unique isoforms of serum transferrin in the patients by Jaeken (1984), more than 120 patients have been diagnosed. The biochemical marker is asialo- and disialo-transferrin. We have found the first Japanese patients and, through analysing serum glycoproteins from these patients, we was noted that multiple serum glycoproteins contain abnormal fractions, on isoelectric focusing. By analysing the sugar chain of transferrin, we have found that the abnormality is caused by a defect in the transfer of asparagine-N-linked oligosaccharide. Recently, two clinical and biochemical variants have been reported. One, characterized by severe mental retardation, no cerebellar hypoplasia, no peripheral neuropathy, diasirotransferrin dominancy, has proven to have a deficiency of N-acetylglucosaminyltransferase II, by Jaeken (1993).
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PMID:[Carbohydrate-deficient glycoprotein syndrome]. 857 56

The clinical features of Angelman syndrome (AS) comprise severe mental retardation, postnatal microcephaly, macrostomia and prognathia, absence of speech, ataxia, and a happy disposition. We report on seven patients who lack most of these features, but presented with obesity, muscular hypotonia and mild mental retardation. Based on the latter findings, the patients were initially suspected of having Prader-Willi syndrome. DNA methylation analysis of SNRPN and D15S63, however, revealed an AS pattern, ie the maternal band was faint or absent. Cytogenetic studies and microsatellite analysis demonstrated apparently normal chromosomes 15 of biparental inheritance. We conclude that these patients have an imprinting defect and a previously unrecognised form of AS. The mild phenotype may be explained by an incomplete imprinting defect or by cellular mosaicism.
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PMID:A previously unrecognised phenotype characterised by obesity, muscular hypotonia, and ability to speak in patients with Angelman syndrome caused by an imprinting defect. 1085 4

Angelman's syndrome is an association of severe mental retardation with absence of language, ataxia, convulsions and hyperactive, joyful behaviour with frequent bouts of laughing. Genetic diagnosis is possible in about 80% of cases. No cardiovascular abnormalities have been described in this syndrome to date. The authors report the cases of three children with Angelman's syndrome who presented with severe malaise due to increased vagal tone. The age of onset of symptoms was between 20 months and 8 years. One of the children had malaises triggered by bouts of laughing. The diagnosis was confirmed in all three cases by the results of Holter 24 hour ECG recording and oculo-cardiac reflex. The treatment chosen was Diphemanil (Prantal) in the two patients under 2 years of age (after failure of a trial of betablockers in one case) and Disopyramide for the oldest child with excellent results in all cases. However, one child died suddenly at the age of 6, two years after stopping diphemanil. Based on these observations, the authors suggest that all malaises in patients with Angelman's syndrome should be investigated by Holter ECG and oculo-cardiac reflex (or tilt test). In view of the potential gravity of the syncopal attacks, long-term medical treatment seems to be justified.
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PMID:[Angelman syndrome and severe vagal hypertonia. Three pediatric case reports]. 1085 53

Rett syndrome, a neurodevelopmental disorder that is a leading cause of mental retardation in females, is caused by mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2). MECP2 mutations have subsequently been identified in patients with a variety of clinical syndromes ranging from mild learning disability in females to severe mental retardation, seizures, ataxia, and sometimes neonatal encephalopathy in males. In classic Rett syndrome, genotype-phenotype correlation studies suggest that X chromosome inactivation patterns have a more prominent effect on clinical severity than the type of mutation. When the full range of phenotypes associated with MECP2 mutations is considered, however, the mutation type strongly affects disease severity. MeCP2 is a transcriptional repressor that binds to methylated CpG dinucleotides throughout the genome, and mutations in Rett syndrome patients are thought to result in at least a partial loss of function. Abnormal gene expression may thus underlie the phenotype. Discovering which genes are misregulated in the absence of functional MeCP2 is crucial for understanding the pathogenesis of this disorder and related syndromes.
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PMID:Molecular genetics of Rett syndrome and clinical spectrum of MECP2 mutations. 1126 31

Angelman syndrome (AS) is a neurodevelopmental disorder characterised by severe mental retardation, absent speech, ataxia, sociable affect, and dysmorphic facial features. Eighty five percent of patients with AS have an identifiable genetic abnormality of chromosome 15q11-13. Mutations within the X linked MECP2 gene have been identified in patients with Rett syndrome (RTT), a neurodevelopmental disorder which affects females almost exclusively and which shares phenotypic overlap with AS. RTT is usually associated with normal development in infancy followed by loss of acquired skills and evolution of characteristic hand wringing movements and episodes of hyperventilation.A panel of 25 female and 22 male patients with a clinical diagnosis of AS and no molecular abnormality of 15q11-13 were screened for MECP2 mutations and these were identified in four females and one male. Following the diagnosis, it was possible to elicit a history of regression in three of these patients, who by then were showing features suggestive of Rett syndrome. In the remaining two subjects the clinical phenotype was still considered to be Angelman-like. These findings illustrate the phenotypic overlap between the two conditions and suggest that screening for MECP2 mutations should be considered in AS patients without a demonstrable molecular or cytogenetic abnormality of 15q11-13. Since MECP2 mutations almost always occur de novo, their identification will substantially affect genetic counselling for the families concerned.
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PMID:Angelman syndrome phenotype associated with mutations in MECP2, a gene encoding a methyl CpG binding protein. 1128 2

Lack of a maternal contribution to the genome at the imprinted domain on proximal chromosome 15 causes Angelman syndrome (AS) associated with neurobehavioral anomalies that include severe mental retardation, ataxia and epilepsy. Although AS patients have infrequent mutations in the gene encoding an E6-AP ubiquitin ligase required for long-term synaptic potentiation (LTP), most cases are attributed to de novo maternal deletions of 15q11-q13. We report here that a novel maternally expressed gene, ATP10C, maps within the most common interval of deletion and that ATP10C expression is virtually absent from AS patients with imprinting mutations, as well as from patients with maternal deletions of 15q11-q13.
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PMID:A novel maternally expressed gene, ATP10C, encodes a putative aminophospholipid translocase associated with Angelman syndrome. 1132 69

A large inbred Lebanese pedigree with congenital spastic ataxia, microcephaly, optic atrophy, short stature, speech defect, abnormal osmiophilic pattern of skin vessels, cerebellar atrophy, and severe mental retardation transmitted as an autosomal recessive trait has been studied. None of the children had any evidence of a metabolic disease, and the analysis of respiratory chain complex abnormalities was unremarkable. Only one child had a history of perinatal difficulties. Differential diagnosis and the possibility that this disorder is a hitherto unreported one are discussed.
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PMID:New autosomal recessive cerebellar ataxia disorder in a large inbred Lebanese family. 1139 56

Congenital cerebellar ataxias are a heterogeneous group of non-progressive disorders characterized by hypotonia and developmental delay followed by the appearance of ataxia, and often associated with dysarthria, mental retardation, and atrophy of the cerebellum. We report the mapping of a disease gene in a large inbred Lebanese Druze family, with five cases of a new form of non-progressive autosomal recessive congenital ataxia associated with optic atrophy, severe mental retardation, and structural skin abnormalities, to a 3.6-cM interval on chromosome 15q24-15q26.
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PMID:A new autosomal recessive non-progressive congenital cerebellar ataxia associated with mental retardation, optic atrophy, and skin abnormalities (CAMOS) maps to chromosome 15q24-q26 in a large consanguineous Lebanese Druze Family. 1203 Mar 28

Angelman syndrome (AS) is a neurodevelopmental disorder characterized by mental retardation, speech impairment, ataxia, and happy disposition with frequent smiling. AS results from the loss of expression of a maternal imprinted gene, UBE3A, mapped within 15q11-q13 region, due to different mechanisms: maternal deletion, paternal UPD, imprinting center mutation, and UBE3A mutation. Deletion AS patients may exhibit hypopigmentation of skin, eye, and hair correlating with deletion of P gene localized in the distal part of Prader-Willi (PWS)/AS region. Our patient presented developmental delay, severe mental retardation, absence of speech, outbursts of laughter, microcephaly, ataxia, hyperactivity, seizures, white skin, no retinal pigmentation, and gold yellow hair. His parents were of African ancestry. The SNURF-SNRPN methylation analysis confirmed AS diagnosis and microsatellite studies disclosed deletion with breakpoints in BP2 and BP3. All of the 25 exons and flanking introns of the P gene of the patient, his father, and mother were investigated. The patient is hemizygous for the deleted exon 7 of the P gene derived from his father who is a carrier of the deleted allele. Our patient manifests OCA2 associated with AS due to the loss of the maternal chromosome 15 with the normal P allele, and the paternal deletion in the P gene. As various degrees of hypopigmentation are associated with PWS and AS patients, the study of the P gene in a hemizygous state could contribute to the understanding of its effect on human pigmentation during development and to disclose the presence of modifier pigmentation gene(s) in the PWS/AS region.
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PMID:Angelman syndrome associated with oculocutaneous albinism due to an intragenic deletion of the P gene. 1274 60


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