Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is estimated that Angelman syndrome (AS) accounts for up to 6% of all children presenting with severe mental retardation and epilepsy. The main clinical features of AS may not be apparent early in life. Clinical findings present in all patients include developmental delay, which becomes apparent by 6-12 months of age, severely impaired expressive language, ataxic gait, tremulousness of limbs, and a typical behavioral profile, including a happy demeanor, hypermotoric behavior, and low attention span. Seizures, abnormal electroencephalography, microcephaly, and scoliosis are observed in >80% of patients. Approximately 70% of patients show a deletion involving the maternally inherited chromosome 15q11-q13, encompassing a cluster of gamma-aminobutyric acid receptor subunit genes, 3% show chromosome 15 paternal uniparental disomy (UPD), 1% harbor a mutation in the imprinting center (a transcriptional regulatory element), and 6% harbor intragenic mutations of the ubiquitin-protein ligase E3A (UBE3A) gene. Twenty percent of patients have no detectable genetic abnormality. Rare cases of familial recurrence of AS show either imprinting center (IC) or UBE3A mutations. Approximately 75% of cases are detected through the methylation test, which allows the detection of AS due to deletions, UPD and IC mutations. Mutation analysis of the UBE3A gene should be performed when the methylation test is negative. Individuals with chromosome 15q11-q13 deletions have a more severe clinical picture and are more prone to develop severe epilepsy. Epilepsy has typical features, including absence and myoclonic seizures, and insidious episodes of nonconvulsive or subtle myoclonic status which are easily overlooked as children appear apathetic or in a state of neurologic regression. Tremulousness, present in all patients even when seizures are well controlled or absent, is related to distal cortical myoclonus. Valproic acid (sodium valproate), benzodiazepines, and ethosuximide, in various combinations, are quite effective in treating the typical seizure types. Piracetam may help in reducing distal myoclonus. Carbamazepine and vigabatrin may seriously aggravate absence and myoclonic seizures and should be avoided. Cognitive, language, and orthopedic problems must be addressed with vigorous rehabilitation programs, including early physical therapy, which may help to develop communicative skills and prevent severe scoliosis and subsequent immobility. Where these treatment strategies are applied, individuals with AS may reach an appreciable level of integration, self care, and have a normal life span.
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PMID:Angelman syndrome: etiology, clinical features, diagnosis, and management of symptoms. 1451 Jun 23

An Internet questionnaire was used to collect data from caregivers about seizure activities and drug therapies of patients with Angelman's syndrome (AS). A questionnaire to collect data on AS patient demographics, seizure types, laboratory diagnosis, and past history of anticonvulsant use was developed and distributed among the membership of multiple AS groups primarily through the Internet. Caregivers of AS patients were asked to rate each drug listed on the questionnaire for its effect on the patient's behavior and alertness and on the severity and frequency of the patient's seizures. A 6-point rating scale was used, with the lowest score representing the most favorable effect. Primary considerations of the survey were to reach as many people as possible, anonymously and quickly, in a widely comprehensible format. Data were collected between March 22 and October 9, 2002. Of the 88 complete questionnaires received, 75 were electronic and 13 were handwritten responses. Forty-seven percent of respondents reported patients' use of a combination of medications at some point, with 59 different combinations described, 21 of which consisted of three or more medications. The most commonly reported regimens were valproic acid and clonazepam, valproic acid and topiramate (with or without clonazepam), valproic acid and lamotrigine, and phenytoin and carbamazepine. Patient characteristics and seizure types were consistent with those of AS patients described in the literature. Topiramate and ethosuximide were rated favorably, consistent with previously published reports. Responses to the questionnaire were widespread and rapid, with 42 responses collected in the first week. An Internet questionnaire helped collect self-reported efficacy information from caregivers of AS patients.
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PMID:Assessment of anticonvulsant effectiveness and safety in patients with Angelman's syndrome using an Internet questionnaire. 1473 75

Angelman syndrome (AS) is an imprinted neurobehavioral disorder characterized by mental retardation, absent speech, excessive laughter, seizures, ataxia, and a characteristic EEG pattern. Classical lesions, including deletion, paternal disomy, or epigenetic mutation, are confirmatory of AS diagnoses in 80% of cases. Loss-of-function mutations of the UBE3A gene have been identified in approximately 8% of AS cases, failing to account for the remaining patient population, and there appears to be a higher prevalence of mutations in familial than sporadic cases. We screened UBE3A in 45 index cases of AS without obvious 15q11-13 abnormalities. Pathological mutations were identified in 3/6 (50%) familial and 4/39 (>10%) sporadic cases. By combining our data with those of the literature, we demonstrate statistically that the frequency of UBE3A mutations is significantly higher in the familial than sporadic subsets of AS. This indicates that an independent molecular mechanism or 'phenocopy' exists for the sporadic group. Rett syndrome (RS), caused by mutations of the MECP2 gene, and patients with deletions of 22q13.3 --> qter, have overlapping clinical features with AS. We screened 24 of the sporadic AS cases without detectable UBE3A mutations for mutations of MECP2, but found none. A separate cohort of 43 atypical patients with features common to AS and RS, in whom 15q11-13 lesions and 22q13.3 --> qter deletion had been ruled out, were also screened for MECP2 mutations. One male patient was mosaic for a frameshift mutation of this gene (previously reported). While MECP2 mutations can cause a phenotype reminiscent of AS in rare cases, they fail to account for the excess of sporadic patients with a definitive clinical diagnosis of AS.
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PMID:Investigation of UBE3A and MECP2 in Angelman syndrome (AS) and patients with features of AS. 1498 18

Angelman syndrome is a severe neurological disorder characterized by mental retardation, absent speech, ataxia, seizures, and hyperactivity. The gene affected in this disorder is UBE3A, the gene encoding the E6-associated protein (E6AP) ubiquitin-protein ligase. Most patients have chromosomal deletions that remove the entire maternal allele of UBE3A. However, a small subset of patients have E6AP point mutations that result in single amino acid changes or short in-frame deletions that still allow translation of a full-length protein. By studying these point mutations in E6AP, we found a strong correlation between Angelman-associated mutations and a loss of E3 ubiquitin ligase activity. Interestingly the point mutations affect E6AP activity in different ways. Some mutant proteins cannot form thiol ester intermediates with ubiquitin, others retain the thiol ester formation activity but cannot efficiently transfer ubiquitin to a substrate, and still others are unstable in cells. Our results suggest that the loss of E6AP catalytic activity and likely the improper regulation of E6AP substrate(s) are important in the development of Angelman syndrome.
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PMID:Biochemical analysis of Angelman syndrome-associated mutations in the E3 ubiquitin ligase E6-associated protein. 1526 5

We report on a girl with monosomy 1p36.3 and Angelman syndrome due to an unbalanced transmission of a maternal balanced chromosomal translocation. She manifested monosomy 1p36 and Angelman syndrome including generalized hypopigmentation, ataxic movements, intractable seizures with characteristic electroencephalographic (EEG) abnormality compatible with Angelman syndrome, and other minor anomalies, large anterior fontanelle, severe psychomotor retardation, and seizures due to monosomy 1p36. Her karyotype was 45, XX, der(1) t(1;15)(p36.31;q13.1),-15, derived from maternal translocation. Molecular analysis determined a breakpoint of 1p between D1S243 and D1S468, which suggested that most genes contributing to the common phenotype are in the distal region.
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PMID:Girl with monosomy 1p36 and Angelman syndrome due to unbalanced der(1) transmission of a maternal translocation t(1;15)(p36.3;q13.1). 1538 94

Angelman syndrome (AS) can result from either a 15q11-q13 deletion (del), paternal uniparental disomy (UPD), imprinting, or UBE3A mutations. Here, we describe the phenotypic and behavioral variability detected in 49 patients with different classes of deletions and nine patients with UPD. Diagnosis was made by methylation pattern analysis of exon 1 of the SNRPN-SNURF gene and by microsatellite profiling of loci within and outside the 15q11-q13 region. There were no major phenotypic differences between the two main classes (BP1-BP3; BP2-BP3) of AS deletion patients, except for the absence of vocalization, more prevalent in patients with BP1-BP3 deletions, and for the age of sitting without support, which was lower in patients with BP2-BP3 deletions. Our data suggest that gene deletions (NIPA1, NIPA2, CYF1P1, GCP5) mapped to the region between breakpoints BP1 and BP2 may be involved in the severity of speech impairment, since all BP1-BP3 deletion patients showed complete absence of vocalization, while 38.1% of the BP2-BP3 deletion patients were able to pronounce syllabic sounds, with doubtful meaning. Compared to UPD patients, deletion patients presented a higher incidence of swallowing disorders (73.9% del x 22.2% UPD) and hypotonia (73.3% del x 28.57% UPD). In addition, children with UPD showed better physical growth, fewer or no seizures, a lower incidence of microcephaly, less ataxia and higher cognitive skills. As a consequence of their milder or less typical phenotype, AS may remain undiagnosed, leading to an overall underdiagnosis of the disease.
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PMID:Phenotypic variability in Angelman syndrome: comparison among different deletion classes and between deletion and UPD subjects. 1547 Mar 70

In the past 6 years, 11 children on valproic acid have developed pancreatitis in our children's hospital. Valproic acid has been used as one of the primary anticonvulsants for generalized seizures in children for the past 25 years. A literature review reveals mostly singular reports of pancreatitis over the past decade. The charts of the 11 patients with valproic acid-induced pancreatitis were reviewed. Dosage, valproic acid serum levels, duration of therapy, and concomitant medications were examined. Families were contacted by telephone to determine the formulation (brand name vs generic) of valproic acid at the time of diagnosis. Six girls and five boys were studied. The ages ranged from 4 to 16 years. Eight of 11 children presented with an acute abdomen. Unexpectedly, three children presented with a flulike illness. Serum lipase values ranged from 341 to 5576 U/L (normal range < 190 U/L). The dose of valproic acid ranged from 20 to 50 mg/kg. Serum levels ranged from 334 to 884 micromol/L (therapeutic range 350-800 micromol/L). Six of the patients were on monotherapy. Seven children were on brand-name drugs. Four of the children had an abnormal neurologic syndromic diagnosis (West syndrome, Rett syndrome, Lowe syndrome, and Angelman's syndrome). Six of the children had a history of drug allergies with a skin rash. Valproic acid was reintroduced in one child and resulted in a second episode of pancreatitis. Resolution of symptoms usually took several weeks following discontinuation of the drug. No association was found with valproic acid dosage, type of preparation, serum levels, duration of therapy, or presence of concomitant medications. Pancreatitis is a severe adverse effect of valproic acid use in children. Dose, duration of treatment, serum valproic acid levels, generic preparation, and the presence of concomitant antiepileptic drugs do not appear to be risk factors. Children with known drug sensitivity might be at risk. Lipase levels at the time of an acute abdomen or a flulike illness in epileptic children taking valproic acid can reveal early stages of pancreatitis and are recommended.
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PMID:Valproic acid-induced pancreatitis in childhood epilepsy: case series and review. 1552 53

Prader-Willi syndrome (PWS) is a complex genetic disorder. About 70% of cases have a paternal deletion at 15q11-q13, and most of the remaining cases are caused by maternal uniparental disomy (UPD). In rare cases of PWS with maternal UPD, small marker chromosomes are identified. Patients with inv dup(15) are at an increased risk of developing PWS or Angelman syndrome (AS) due to UPD. They may be also at increased risk for developmental delay due to additional copies of genes located within the PWS/AS critical region. Therefore, molecular investigations in patients with a supernumerary marker chromosome (SMC) are necessary to provide proper genetic counseling. We report a female infant with central hypotonia, weak crying, feeding problems, failure to thrive, and developmental delay after birth. Chromosome analysis revealed an SMC in 55% of metaphase cells. Fluorescence in situ hybridization showed that this marker chromosome was constituted by a small isodicentric inverted duplication of chromosome 15 [inv dup(15)]. Microsatellite analysis showed uniparental isodisomy of maternal chromosome 15 in the proband. Diagnosis of PWS was further confirmed by methylation-specific polymerase chain reaction. The inv dup(15) marker chromosome was also of maternal origin. Follow-up at the age of 18 months revealed a height in the 10th percentile and weight in the 50th percentile. She had poor activity and muscle tone, and was unable to walk independently. There was no psychomotor retardation, behavior disturbance or seizure.
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PMID:Maternal uniparental disomy in a patient with Prader-Willi syndrome with an additional small inv dup(15) chromosome. 1562 46

Angelman syndrome is one of the most studied human diseases related to a gene that is expressed on the maternal chromosome only in at least some brain cells. It is caused by inactivation of the UBE3A gene in the brain due to various abnormalities of the 15q11-q13 chromosome inherited from the mother. It is characterized by severe developmental delay, seizures, virtual absence of speech, motor impairment, and a particular behavioral phenotype. Studies of cortical, electromyographic and cerebellar electrophysiology in patients with Angelman syndrome and a mouse model revealed unique rhythmic neurophysiological activities in the cerebral cortex, cerebellar cortex, and muscles. The oscillatory patterns may be linked to molecular pathophysiology of the syndrome involving dysregulation of synaptic neurotransmission through UBE3A-related modulation of functional GABAA receptor complexes.
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PMID:From electrophysiology to chromatin: a bottom-up approach to Angelman syndrome. 1565 43

Angelman syndrome (AS) is a genetic disorder characterised by severe mental retardation, subtle dysmorphic facial features, a characteristic behavioural phenotype, epileptic seizures and EEG abnormalities. AS can be caused by various genetic mechanisms involving the chromosome 15q11-13 region. Neurophysiological studies report a variety of EEG abnormalities seen in AS patients. The objective of this article was to analyse whether there are characteristic EEG changes in AS, whether this varies with age and what the differential diagnosis is. Most of the authors agree about the existence of three main EEG patterns in AS which may appear in isolation or in various combinations in the same patient. The pattern most frequently observed both in children and in adults has prolonged runs of high amplitude rhythmic 2-3 Hz activity predominantly over the frontal regions with superimposed interictal epileptiform discharges. High amplitude rhythmic 4-6 Hz activity, prominent in the occipital regions, with spikes, which can be facilitated by eye closure, is often seen in children under the age of 12 years. There is no difference in EEG findings in AS patients with or without epileptic seizures. AS patients with a deletion of chromosome 15q11-13 have more prominent EEG abnormalities than patients with other genetic disturbances of the chromosome 15 region. The EEG findings are characteristic of AS when seen in the appropriate clinical context and can help to identify AS patients at an early age when genetic counselling may be particularly important.
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PMID:Angelman syndrome: is there a characteristic EEG? 1566 45


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