RESUMEN
Adaptive nanopore sequencing as a diagnostic method for imprinting disorders and episignature analysis revealed an intragenic duplication of Exon 6 and 7 in UBE3A (NM_000462.5) in a patient with relatively mild Angelman-like syndrome. In an all-in-one nanopore sequencing analysis DNA hypomethylation of the SNURF:TSS-DMR, known contributing deletions on the maternal allele and point mutations in UBE3A could be ruled out as disease drivers. In contrast, breakpoints and orientation of the tandem duplication could clearly be defined. Segregation analysis in the family showed that the duplication derived de novo in the maternal grandfather. Our study shows the benefits of an all-in-one nanopore sequencing approach for the diagnostics of Angelman syndrome and other imprinting disorders.
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Síndrome de Angelman , Metilación de ADN , Duplicación de Gen , Secuenciación de Nanoporos , Ubiquitina-Proteína Ligasas , Humanos , Síndrome de Angelman/genética , Síndrome de Angelman/diagnóstico , Ubiquitina-Proteína Ligasas/genética , Secuenciación de Nanoporos/métodos , Metilación de ADN/genética , Femenino , Duplicación de Gen/genética , Masculino , Exones/genética , Linaje , Impresión Genómica/genéticaRESUMEN
AIMS: Caregivers rate improved communication ability as one of the most desired outcomes for successful interventions for individuals with Angelman syndrome (AS). When measuring communication ability in clinical trials, the reliability of such measures is critical for detecting significant changes over time. This study examined the reliability of the Observed-Reported Communication Ability (ORCA) measure completed by caregivers of individuals with AS. METHODS: The ORCA measure was completed by 249 caregivers with 170 caregivers completing the ORCA measure again after 5-12 days. Generalizability theory was used to examine the following sources of measurement error in ORCA scores: concepts, subdomains, assessment points, and the interactions among those facets and the object of measurement: communication ability. Three generalizability studies were conducted to understand the reliability of the ORCA measure for different measurement designs. Decision studies were carried out to demonstrate the optimization of measurement procedures of the ORCA measure. RESULTS: G and Phi coefficients of the original measurement design exceeded the 0.80 threshold considered sufficiently reliable to make relative and absolute decisions about the communication ability of individuals with AS based on their caregivers' observed scores. The optimization procedures indicated that increasing the number of communication concepts and/or assessment points leads to more reliable estimates of communication. CONCLUSION: The ORCA measure was able to reliably distinguish different levels of communication ability among individuals with AS. Multiple assessment points and or more concepts would provide more precise estimates of an individual's communication ability but at the cost of survey fatigue.
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Síndrome de Angelman , Cuidadores , Comunicación , Humanos , Síndrome de Angelman/diagnóstico , Cuidadores/psicología , Reproducibilidad de los Resultados , Masculino , Femenino , Niño , Adulto , Adolescente , Preescolar , Psicometría/métodos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
BACKGROUND: Diagnosing imprinting defects in neonates and young children presents challenges, often necessitating molecular analysis for a conclusive diagnosis. The isolation of genetic material from oral swabs becomes crucial, especially in settings where blood sample collection is impractical or for vulnerable populations like newborns, who possess limited blood volumes and are often too fragile for invasive procedures. Oral swab samples emerge as an excellent source of DNA, effectively overcoming obstacles associated with rare diseases. METHODS: In our study, we specifically addressed the determination of the quality and quantity of DNA extracted from oral swab samples using NaCl procedures. RESULTS: We compared these results with extractions performed using a commercial kit. Subsequently, the obtained material underwent MS-HRM analysis for loci associated with imprinting diseases such as Prader-Willi and Angelman syndromes. CONCLUSIONS: Our study emphasizes the significance of oral swab samples as a reliable source for obtaining DNA for MS-HRM analysis. NaCl extraction stands out as a practical and cost-effective method for genetic studies, contributing to a molecular diagnosis that proves particularly beneficial for patients facing delays in characterization, ultimately influencing their treatment.
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Síndrome de Angelman , ADN , Impresión Genómica , Mucosa Bucal , Síndrome de Prader-Willi , Humanos , Mucosa Bucal/citología , Mucosa Bucal/patología , Síndrome de Angelman/genética , Síndrome de Angelman/diagnóstico , Síndrome de Prader-Willi/genética , Síndrome de Prader-Willi/diagnóstico , ADN/genética , ADN/aislamiento & purificación , Cloruro de Sodio , Recién Nacido , Masculino , Trastornos de ImprontaRESUMEN
INTRODUCTION: Long-read whole genome sequencing like Oxford Nanopore Technology, is increasingly being introduced in clinical settings. With its ability to simultaneously call sequence variation and DNA modifications including 5-methylcytosine, nanopore is a promising technology to improve diagnostics of imprinting disorders. METHODS: Currently, no tools to analyze DNA methylation patterns at known clinically relevant imprinted regions are available. Here we present NanoImprint, which generates an easily interpretable report, based on long-read nanopore sequencing, to use for identifying clinical relevant abnormalities in methylation levels at 14 imprinted regions and diagnosis of common imprinting disorders. RESULTS AND CONCLUSION: NanoImprint outputs a summarizing table and visualization plots displays methylation frequency (%) and chromosomal positions for all regions, with phased data color-coded for the two alleles. We demonstrate the utility of NanoImprint using three imprinting disorder samples from patients with Beckwith-Wiedemann syndrome (BWS), Angelman syndrome (AS) and Prader-Willi syndrome (PWS). NanoImprint script is available from https://github.com/carolinehey/NanoImprint.
Asunto(s)
Síndrome de Angelman , Síndrome de Beckwith-Wiedemann , Metilación de ADN , Impresión Genómica , Secuenciación de Nanoporos , Síndrome de Prader-Willi , Humanos , Secuenciación de Nanoporos/métodos , Síndrome de Angelman/genética , Síndrome de Angelman/diagnóstico , Síndrome de Prader-Willi/genética , Síndrome de Prader-Willi/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Síndrome de Beckwith-Wiedemann/diagnóstico , Análisis de Secuencia de ADN/métodos , Nanoporos , Trastornos de ImprontaRESUMEN
BACKGROUND: Overactivity is prevalent in several rare genetic neurodevelopmental syndromes, including Smith-Magenis syndrome, Angelman syndrome, and tuberous sclerosis complex, although has been predominantly assessed using questionnaire techniques. Threats to the precision and validity of questionnaire data may undermine existing insights into this behaviour. Previous research indicates objective measures, namely actigraphy, can effectively differentiate non-overactive children from those with attention-deficit hyperactivity disorder. This study is the first to examine the sensitivity of actigraphy to overactivity across rare genetic syndromes associated with intellectual disability, through comparisons with typically-developing peers and questionnaire overactivity estimates. METHODS: A secondary analysis of actigraphy data and overactivity estimates from The Activity Questionnaire (TAQ) was conducted for children aged 4-15 years with Smith-Magenis syndrome (N=20), Angelman syndrome (N=26), tuberous sclerosis complex (N=16), and typically-developing children (N=61). Actigraphy data were summarized using the M10 non-parametric circadian rhythm variable, and 24-hour activity profiles were modelled via functional linear modelling. Associations between actigraphy data and TAQ overactivity estimates were explored. Differences in actigraphy-defined activity were also examined between syndrome and typically-developing groups, and between children with high and low TAQ overactivity scores within syndromes. RESULTS: M10 and TAQ overactivity scores were strongly positively correlated for children with Angelman syndrome and Smith-Magenis syndrome. M10 did not substantially differ between the syndrome and typically-developing groups. Higher early morning activity and lower evening activity was observed across all syndrome groups relative to typically-developing peers. High and low TAQ group comparisons revealed syndrome-specific profiles of overactivity, persisting throughout the day in Angelman syndrome, occurring during the early morning and early afternoon in Smith-Magenis syndrome, and manifesting briefly in the evening in tuberous sclerosis complex. DISCUSSION: These findings provide some support for the sensitivity of actigraphy to overactivity in children with rare genetic syndromes, and offer syndrome-specific temporal descriptions of overactivity. The findings advance existing descriptions of overactivity, provided by questionnaire techniques, in children with rare genetic syndromes and have implications for the measurement of overactivity. Future studies should examine the impact of syndrome-related characteristics on actigraphy-defined activity and overactivity estimates from actigraphy and questionnaire techniques.
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Síndrome de Angelman , Discapacidad Intelectual , Síndrome de Smith-Magenis , Esclerosis Tuberosa , Niño , Humanos , Síndrome de Smith-Magenis/complicaciones , Síndrome de Angelman/complicaciones , Síndrome de Angelman/diagnóstico , Esclerosis Tuberosa/complicaciones , Discapacidad Intelectual/complicacionesRESUMEN
Hyperphagia is highly penetrant in Prader-Willi syndrome (PWS) and has increasingly been reported in other neurogenetic conditions (NGC). The Hyperphagia Questionnaire (HQ) was completed by caregivers of 4-8-year-olds with PWS (n = 17), Angelman syndrome (AS; n = 22), Williams syndrome (WS; n = 25), or low-risk controls (LRC; n = 35). All NGC groups were significantly elevated in HQ Total and Behavior scores compared to LRC. Only AS and WS were significantly elevated in the Drive domain, and only PWS in the Severity domain. After controlling for externalizing behavior, HQ Total scores were higher for PWS relative to other groups. Hyperphagic symptoms may not differentiate PWS from other NGCs in early childhood. However, hyperphagic phenotypes may be most severe in PWS. Further investigation of these profiles may inform etiology and syndrome-specific treatments.
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Síndrome de Angelman , Hiperfagia , Síndrome de Prader-Willi , Humanos , Preescolar , Masculino , Femenino , Síndrome de Prader-Willi/diagnóstico , Niño , Síndrome de Angelman/fisiopatología , Síndrome de Angelman/diagnósticoRESUMEN
BACKGROUND: Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by severe intellectual disability, little to no expressive speech, visual and motor problems, emotional/behavioral challenges, and a tendency towards hyperphagia and weight gain. The characteristics of AS make it difficult to measure these children's functioning with standard clinical tests. Feasible outcome measures are needed to measure current functioning and change over time, in clinical practice and clinical trials. AIM: Our first aim is to assess the feasibility of several functional tests. We target domains of neurocognitive functioning and physical growth using the following measurement methods: eye-tracking, functional Near-Infrared Spectroscopy (fNIRS), indirect calorimetry, bio-impedance analysis (BIA), and BOD POD (air-displacement plethysmography). Our second aim is to explore the results of the above measures, in order to better understand the AS phenotype. METHODS: The study sample consisted of 28 children with AS aged 2-18 years. We defined an outcome measure as feasible when (1) at least 70% of participants successfully finished the measurement and (2) at least 60% of those participants had acceptable data quality. Adaptations to the test procedure and reasons for early termination were noted. Parents rated acceptability and importance and were invited to make recommendations to increase feasibility. The results of the measures were explored. RESULTS: Outcome measures obtained with eye-tracking and BOD POD met the definition of feasibility, while fNIRS, indirect calorimetry, and BIA did not. The most important reasons for early termination of measurements were showing signs of protest, inability to sit still and poor/no calibration (eye-tracking specific). Post-calibration was often applied to obtain valid eye-tracking results. Parents rated the BOD POD als most acceptable and fNIRS as least acceptable for their child. All outcome measures were rated to be important. Exploratory results indicated longer reaction times to high salient visual stimuli (eye-tracking) as well as high body fat percentage (BOD POD). CONCLUSIONS: Eye-tracking and BOD POD are feasible measurement methods for children with AS. Eye-tracking was successfully used to assess visual orienting functions in the current study and (with some practical adaptations) can potentially be used to assess other outcomes as well. BOD POD was successfully used to examine body composition. TRIAL REGISTRATION: Registered d.d. 23-04-2020 under number 'NL8550' in the Dutch Trial Register: https://onderzoekmetmensen.nl/en/trial/23075.
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Síndrome de Angelman , Niño , Humanos , Síndrome de Angelman/complicaciones , Síndrome de Angelman/diagnóstico , Reproducibilidad de los Resultados , Composición Corporal , Pletismografía/métodos , Impedancia EléctricaRESUMEN
Angelman syndrome (AS, MIM #105830) is a neurodevelopmental disorder characterized by severe intellectual disability, profound developmental delay, movement or balance problems, an excessively cheerful disposition, and seizures. AS results from inadequate expression of the maternal UBE3A gene (MIM #601623), which encodes an E3 ligase in the ubiquitin-proteasome pathway. Here we present the case of two sisters with features consistent with AS who had negative methylation analyses. An autism/intellectual disability expanded panel revealed a maternally inherited novel UBE3A (NM_001354506.2) variant c.2443C>T p.(Pro815Ser) in both patients that was initially classified as a variant of uncertain significance. The patients were enrolled in Indiana University's Undiagnosed Rare Disease Clinic (URDC) to further investigate the variant. Additional data, including deep phenotyping, familial segregation analysis, and in silico studies, suggest that the variant is likely pathogenic. 3D modeling studies based on the available crystal structure revealed that the Pro815Ser variant can introduce more flexibility into the protein and alter its enzymatic activity. Recent literature confirms the pathogenic nature of the variant. Reanalysis of the UBE3A variant has heightened existing knowledge of AS and has offered this family an end to their diagnostic odyssey.
Asunto(s)
Síndrome de Angelman , Hermanos , Ubiquitina-Proteína Ligasas , Humanos , Síndrome de Angelman/genética , Síndrome de Angelman/diagnóstico , Femenino , Ubiquitina-Proteína Ligasas/genética , Enfermedades Raras/genética , Enfermedades Raras/diagnóstico , Fenotipo , Linaje , Mutación , Niño , Discapacidad Intelectual/genética , Discapacidad Intelectual/diagnóstico , Predisposición Genética a la Enfermedad , PreescolarRESUMEN
PURPOSE: To investigate the relationship between the details of strabismus and orbital abnormalities determined by ocular motility tests and orbital imaging examinations in 9 cases with Angelman syndrome (AS). STUDY DESIGN: A retrospective, clinical report. METHODS: The 9 AS cases (mean age at initial visit: 4.6 ± 8.0 years) were confirmed by genetic diagnosis of the chromosome 15q11-13 region. In all cases, axial imaging of the orbit in the transverse plane of the horizontal extraocular muscles was obtained. The opening angle between both lateral walls of the orbit (greater wing of sphenoid) was measured as the biorbital angle, and compared with the 95% confidence interval of the orbital angle in normal children. RESULTS: All cases had exotropia with means of the distance and near of angle 32.2 prism diopters (Δ) ± 9.7Δ and 32.8Δ ± 8.3Δ. The mean of the biorbital angle was 107.7° ± 7.6°, greater than the biorbital angle of 94.3° ± 5.1° previously reported in 129 normal children (P < 0.0001, t-test). Except for one biorbital angle of 93° in the 25-year-old patient, all the biorbital angles in the 8 children were larger than the upper 95% confidence interval in normal children. Astigmatic and hyperopic ametropic amblyopia were detected in 3 cases and 1 case, respectively. CONCLUSIONS: The frequency of exotropia in AS is higher than previously reported, with our results strongly suggesting that the enlarged biorbital angle is related to the pathogenesis of exotropia in AS.
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Síndrome de Angelman , Exotropía , Enfermedades Orbitales , Estrabismo , Niño , Humanos , Preescolar , Adulto , Exotropía/diagnóstico , Exotropía/etiología , Síndrome de Angelman/complicaciones , Síndrome de Angelman/diagnóstico , Estudios Retrospectivos , Estrabismo/etiología , Estrabismo/complicaciones , Músculos Oculomotores/diagnóstico por imagen , Procedimientos Quirúrgicos Oftalmológicos/métodosRESUMEN
OBJECTIVE: The objective of this study was to identify the age of diagnosis for children with one of three neurogenetic conditions resulting from changes in chromosome 15 (Angelman syndrome [AS], Prader-Willi syndrome [PWS], and duplication 15q syndrome [Dup15q]). METHODS: Data about the diagnostic process for each condition were contributed by the advocacy organizations. Median and interquartile ranges were calculated for each condition by molecular subtype and year. Comparison tests were run to explore group differences. RESULTS: The median age of diagnosis was 1.8 years for both AS and Dup15q. PWS was diagnosed significantly younger at a median age of 1 month. Deletion subtypes for both PWS and AS were diagnosed earlier than nondeletion subtypes, and children with isodicentric duplications in Dup15q were diagnosed earlier than those with interstitial duplications. CONCLUSION: Understanding variability in the age of diagnosis for chromosome 15 disorders is an important step in reducing the diagnostic odyssey and improving access to interventions for these populations. Results from this study provide a baseline by which to evaluate efforts to reduce the age of diagnosis for individuals with these conditions.
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Síndrome de Angelman , Trastornos de los Cromosomas , Síndrome de Prader-Willi , Humanos , Niño , Lactante , Síndrome de Prader-Willi/diagnóstico , Síndrome de Prader-Willi/genética , Trastornos de los Cromosomas/diagnóstico , Trastornos de los Cromosomas/genética , Cromosomas , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/genética , TrisomíaRESUMEN
PURPOSE: Angelman Syndrome (AS) is a rare, severe neurogenetic disorder that causes symptoms such as intellectual disability and motor impairments and is typically diagnosed in early childhood. The complexity and heterogeneity of AS confound characterization of disease severity and pose unique challenges when determining an individual's response to treatment. There is therefore a substantial unmet need for rating scales specifically designed for complex conditions such as AS. To address this, the Clinical Global Impressions (CGI) scale, which has components for both symptom severity (CGI-S) and improvement (CGI-I) was specifically adapted to measure severity (CGI-S-AS) and improvement (CGI-I-AS) in AS. METHODS: The modified CGI-S/I-AS was used in the NEPTUNE trial of gaboxadol for the treatment of AS. Here we report on the validation of the CGI-I-AS using data from NEPTUNE and discuss insights for its potential use in future trials. RESULTS: Improvements in the CGI-I-AS rating tended to be consistent with changes on other relevant rating scales. Sleep-related symptoms were particularly well represented, while communication-related symptoms were not. CONCLUSIONS: Our validation analysis of the CGI-I-AS demonstrates its usefulness along with possible areas of improvement. The CGI-I-AS is a potential tool for use in other trials of AS drug candidates, and the process for its development can serve as a road map for the development of assessment tools for other neuropsychiatric disorders with similar complexities and heterogeneity.
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Síndrome de Angelman , Preescolar , Humanos , Síndrome de Angelman/diagnóstico , Escalas de Valoración Psiquiátrica , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Ensayos Clínicos como AsuntoRESUMEN
Angelman Syndrome is a rare neurodevelopmental disorder characterized by developmental delay, lack of speech, seizures, intellectual disability, characteristic behavior, and movement disorders. Clinical gait analysis provides the opportunity for movement quantification to investigate an observed maladaptive change in gait pattern and offers an objective outcome of change. Pressure-sensor-based technology, inertial and activity monitoring, and instrumented gait analysis (IGA) were employed to define motor abnormalities in Angelman syndrome. Temporal-spatial gait parameters of persons with Angelman Syndrome (pwAS) show deficiencies in gait performance through walking speed, step length, step width, and walk ratio. pwAS walk with reduced step lengths, increased step width, and greater variability. Three-dimensional motion kinematics showed increased anterior pelvic tilt, hip flexion, and knee flexion. PwAS have a walk ratio more than two standard deviations below controls. Dynamic electromyography showed prolonged activation of knee extensors, which was associated with a decreased range of motion and the presence of hip flexion contractures. Use of multiple gait tracking modalities revealed that pwAS exhibit a change in gait pattern to a flexed knee gait pattern. Cross-sectional studies of individuals with AS show a regression toward this maladaptive gait pattern over development in pwAS ages 4-11. PwAS unexpectedly did not have spasticity associated with change in gait pattern. Multiple quantitative measures of motor patterning may offer early biomarkers of gait decline consistent with critical periods of intervention, insight into appropriate management strategies, objective primary outcomes, and early indicators of adverse events.
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Síndrome de Angelman , Humanos , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/genética , Estudios Transversales , Caminata/fisiología , Marcha/fisiología , Articulación de la Rodilla , Fenómenos BiomecánicosRESUMEN
INTRODUCTION: Angelman syndrome (AS) is widely described in childhood, but few studies have been conducted in adulthood and most of them report a small number of patients or specific conditions, such as epilepsy or sleep. AIM: The aim of this study is to describe AS in adulthood in our centre, the special needs it requires, and the medical and social support to improve care and to provide a better transition from the paediatric service to units for adults. PATIENTS AND METHODS: We collected patients with genetically confirmed AS, and described demographic, medical and social data by reviewing medical records, telephone interviews with the primary caregiver and three standardised sleep, dependency and quality of life scales. RESULTS: Thirty patients with a median age of 22.7 years were included: 22 were deletions, 27 had a history of epilepsy and 13 were on treatment involving at least two antiepileptic drugs. The most frequent comorbidities after epilepsy were psychiatric symptoms, scoliosis, overweight, constipation and ophthalmological problems. Forty per cent required hospital admissions in adulthood, five were institutionalised and 24 received non-medical therapies. The doctor in charge was the neurologist in most cases, followed by the neuropaediatrician. CONCLUSIONS: Studies that examine the natural history beyond childhood are warranted. This is the first Spanish review of adults with AS that covers a broad spectrum of social and medical conditions of these patients.
TITLE: Síndrome de Angelman en el adulto.Introducción. El síndrome de Angelman (SA) está ampliamente descrito en la infancia, pero existen escasos estudios en edad adulta y la mayoría recoge un pequeño número de pacientes o condiciones específicas, como epilepsia o sueño. Objetivo. El objetivo de este estudio es describir el SA en la edad adulta en nuestro centro, sus necesidades especiales, y el soporte médico y social para mejorar la atención y ofrecer una mejor transición del servicio de pediatría a las unidades de adultos. Pacientes y métodos. Se recogen pacientes con SA genéticamente confirmado, y describimos datos demográficos, médicos y sociales mediante la revisión de historias clínicas, entrevistas telefónicas con el cuidador principal y tres escalas estandarizadas de sueño, dependencia y calidad de vida. Resultados. Se incluye a 30 pacientes con una mediana de edad de 22,7 años: 22 son deleciones, 27 presentan antecedente de epilepsia y 13 están en tratamiento con, al menos, dos fármacos antiepilépticos. Las comorbilidades más frecuentes después de la epilepsia fueron los síntomas psiquiátricos, la escoliosis, el sobrepeso, el estreñimiento y problemas oftalmológicos. El 40% precisó ingresos hospitalarios en la edad adulta, cinco están institucionalizados y 24 reciben terapias no médicas. El médico a cargo es el neurólogo en la mayoría, seguido del neuropediatra. Conclusiones. Es necesario realizar estudios de historia natural más allá de la infancia. Ésta es la primera revisión española de adultos con SA que recoge un amplio espectro de condiciones sociales y médicas de estos pacientes.
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Síndrome de Angelman , Epilepsia , Trastornos Mentales , Adulto , Niño , Humanos , Adulto Joven , Síndrome de Angelman/diagnóstico , Calidad de Vida , Epilepsia/epidemiología , ComorbilidadRESUMEN
Recurrent de novo missense variants in H4 histone genes have recently been associated with a novel neurodevelopmental syndrome that is characterized by intellectual disability and developmental delay as well as more variable findings that include short stature, microcephaly, and facial dysmorphisms. A 4-year-old male with autism, developmental delay, microcephaly, and a happy demeanor underwent evaluation through the Undiagnosed Disease Network. He was clinically suspected to have Angelman syndrome; however, molecular testing was negative. Genome sequencing identified the H4 histone gene variant H4C5 NM_003545.4: c.295T>C, p.Tyr99His, which parental testing confirmed to be de novo. The variant met criteria for a likely pathogenic classification and is one of the seven known disease-causing missense variants in H4C5. A comparison of our proband's findings to the initial description of the H4-associated neurodevelopmental syndrome demonstrates that his phenotype closely matches the spectrum of those reported among the 29 affected individuals. As such, this report corroborates the delineation of neurodevelopmental syndrome caused by de novo missense H4 gene variants. Moreover, it suggests that cases of clinically suspected Angelman syndrome without molecular confirmation should undergo exome or genome sequencing, as novel neurodevelopmental syndromes with phenotypes overlapping with Angelman continue to be discovered.
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Síndrome de Angelman , Discapacidad Intelectual , Microcefalia , Trastornos del Neurodesarrollo , Masculino , Humanos , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/genética , Microcefalia/genética , Histonas/genética , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Fenotipo , Trastornos del Neurodesarrollo/diagnóstico , Trastornos del Neurodesarrollo/genética , Mutación Missense/genéticaRESUMEN
The CpG island flanking the promoter region of SNRPN on chromosome 15q11.2 contains CpG sites that are completely methylated in the maternally derived allele and unmethylated in the paternally derived allele. Both unmethylated and methylated alleles are observed in normal individuals. Only the methylated allele is observed in patients with Prader-Willi syndrome, whereas only the unmethylated allele is observed in those with Angelman syndrome. Hence, detection of aberrant methylation at the differentially methylated region is fundamental to the molecular diagnosis of Prader-Willi syndrome and Angelman syndromes. Traditionally, bisulfite treatment and methylation-sensitive restriction enzyme treatment or methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) have been used. We here developed a long-read sequencing assay that can distinguish methylated and unmethylated CpG sites at 15q11.2 by the difference in current intensity generated from nanopore reads. We successfully diagnosed 4 Prader-Willi syndrome patients and 3 Angelman syndrome patients by targeting differentially methylated regions. Concurrent copy number analysis, homozygosity analysis, and structural variant analysis also allowed us to precisely delineate the underlying pathogenic mechanisms, including gross deletion, uniparental heterodisomy, uniparental isodisomy, or imprinting defect. Furthermore, we showed allele-specific methylation in imprinting-related differentially methylated regions on chromosomes 6, 7, 11, 14, and 20 in a normal individual together with 4 Prader-Willi patients and 3 Angelman syndrome patients. Hence, presently reported method is likely to be applicable to the diagnosis of imprinting disorders other than Prader-Willi syndrome and Angelman syndrome as well.
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Síndrome de Angelman , Nanoporos , Síndrome de Prader-Willi , Humanos , Síndrome de Prader-Willi/diagnóstico , Síndrome de Prader-Willi/genética , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/genética , Metilación de ADN , Disomía Uniparental , Cromosomas Humanos Par 15/genética , Impresión GenómicaRESUMEN
The goal of these studies was to use quantitative (q)EEG techniques on data from children with Angelman syndrome (AS) using spectral power analysis, and to evaluate this as a potential biomarker and quantitative method to evaluate therapeutics. Although characteristic patterns are evident in visual inspection, using qEEG techniques has the potential to provide quantitative evidence of treatment efficacy. We first assessed spectral power from baseline EEG recordings collected from children with AS compared to age-matched neurotypical controls, which corroborated the previously reported finding of increased total power driven by elevated delta power in children with AS. We then retrospectively analyzed data collected during a clinical trial evaluating the safety and tolerability of minocycline (3 mg/kg/d) to compare pretreatment recordings from children with AS (4-12 years of age) to EEG activity at the end of treatment and following washout for EEG spectral power and epileptiform events. At baseline and during minocycline treatment, the AS subjects demonstrated increased delta power; however, following washout from minocycline treatment the AS subjects had significantly reduced EEG spectral power and epileptiform activity. Our findings support the use of qEEG analysis in evaluating AS and suggest that this technique may be useful to evaluate therapeutic efficacy in AS. Normalizing EEG power in AS therefore may become an important metric in screening therapeutics to gauge overall efficacy. As therapeutics transition from preclinical to clinical studies, it is vital to establish outcome measures that can quantitatively evaluate putative treatments for AS and neurological disorders with distinctive EEG patterns.
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Síndrome de Angelman , Niño , Humanos , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/tratamiento farmacológico , Electroencefalografía , Minociclina/uso terapéutico , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The study characterised differences in costs associated with raising a child between four rare disorders and examined the associations between these costs with clinical severity. Caregivers of 108 individuals with Prader-Willi, Angelman (AS), Chromosome 15q Duplication and fragile X (FXS) syndromes completed a modified Client Services Receipt Inventory and participants completed intellectual/developmental functioning and autism assessments. AS incurred the highest yearly costs per individual ($AUD96,994), while FXS had the lowest costs ($AUD33,221). Intellectual functioning negatively predicted total costs, after controlling for diagnosis. The effect of intellectual functioning on total costs for those with AS was significantly different to the other syndromes. The study highlights the significant costs associated with these syndromes, particularly AS, linked with severity of intellectual functioning.
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Síndrome de Angelman , Trastorno del Espectro Autista , Síndrome del Cromosoma X Frágil , Síndrome de Prader-Willi , Niño , Humanos , Síndrome de Prader-Willi/diagnóstico , Síndrome de Prader-Willi/genética , Síndrome de Prader-Willi/complicaciones , Cromosomas Humanos Par 15/genética , Trastorno del Espectro Autista/complicaciones , Síndrome del Cromosoma X Frágil/diagnóstico , Síndrome del Cromosoma X Frágil/genética , Síndrome del Cromosoma X Frágil/complicaciones , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/genética , Australia , Duplicación CromosómicaRESUMEN
We describe the development of 236 children with Angelman syndrome (AS) using the Bayley Scales of Infant and Toddler Development, Third Edition. Multilevel linear mixed modeling approaches were used to explore differences between molecular subtypes and over time. Individuals with AS continue to make slow gains in development through at least age 12 years of age at about 1-2 months/year based on age equivalent score and 1-16 growth score points/year depending on molecular subtype and domain. Children with a deletion have lower scores at baseline and slower rate of gaining skills while children with UBE3A variant subtype demonstrated higher scores as well as greater rates of skill attainment in all domains. The developmental profiles of UPD and ImpD were similar.
Asunto(s)
Síndrome de Angelman , Trastorno del Espectro Autista , Lactante , Niño , Humanos , Discapacidades del Desarrollo/diagnóstico , Destreza Motora , Síndrome de Angelman/diagnóstico , Síndrome de Angelman/genética , Desarrollo InfantilRESUMEN
BACKGROUND: Angelman syndrome (AS) occurs due to a lack of expression or function of the maternally inherited UBE3A gene. Individuals with AS typically have significant developmental delay, severe speech impairment with absent to minimal verbal language, gait abnormalities including ataxia, and an incongruous happy demeanor. The majority of individuals with AS also have seizures and microcephaly. Some individuals with mosaic AS have been reported to have expressive language and milder levels of developmental delay. CASE REPORT: We report a male patient presenting with mild to moderate intellectual disability, hyperphagia, obesity, and the ability to communicate verbally. His phenotype was suggestive of Prader-Willi syndrome. However, methylation testing was positive for Angelman syndrome and additional methylation specific multiplex ligation-dependent amplification (MS-MLPA) study revealed low-level mosaicism for AS. CONCLUSION: A broader phenotypic spectrum should be considered for AS as patients with atypical presentations may otherwise elude diagnosis.