191 research outputs found
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A placebo-controlled trial of folic acid and betaine in identical twins with Angelman syndrome.
BackgroundAngelman syndrome (AS) is a neurodevelopmental disorder that is caused by maternal genetic deficiency of a gene that encodes E6-AP ubiquitin-protein ligase (gene symbol UBE3A) mapping to chromosome 15q11-q13. AS leads to stiff and jerky gait, excess laughter, seizures, and severe intellectual disability. In some parts of the brain, the paternally inherited UBE3A gene is subject to genomic imprinting by the action of the UBE3A-antisense transcript (UBE3A-ATS) on the paternally inherited allele. Consequently, only the maternally inherited UBE3A gene is expressed in mature neurons. AS occurs due to deletions of the maternal 15q11 - 13 region, paternal uniparental disomy (UPD), imprinting center defects, mutations in the maternal UBE3A gene, or other unknown genetic malfunctions that result in a silenced maternal UBE3A gene in the specific imprinted regions of the brain.ResultsA potential treatment strategy for AS is to increase methylation of UBE3A-ATS to promote expression of the paternal UBE3A gene and thus ameliorate the clinical phenotypes of AS. We treated two sets of male identical twins with class I deletions with a 1 year treatment trial of either betaine and folic acid versus placebo. We found no statistically significant changes in the clinical parameters tested at the end of the 1 year trial, nor did we find any significant adverse events.ConclusionsThis study tested the hypothesis that by increasing the methylation of the UBE3A-antisense transcript in Angelman syndrome to promote expression of the silenced paternal UBE3A gene we may ameliorate the clinical phenotypes of AS. We treated two sets of identical twins with placebo versus betaine and folic acid. Although this study represented a novel approach to treating Angelman syndrome, the differences in the developmental testing results was not significant. This paper also discusses the value of monozygotic twin studies in minimizing confounding variables and its utility in conducting small treatment studies.Trial registrationNCT00348933 . Registered 6 July 2006
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Further evidence for the involvement of EFL1 in a Shwachman-Diamond-like syndrome and expansion of the phenotypic features.
Recent evidence has implicated EFL1 in a phenotype overlapping Shwachman-Diamond syndrome (SDS), with the functional interplay between EFL1 and the previously known causative gene SBDS accounting for the similarity in clinical features. Relatively little is known about the phenotypes associated with pathogenic variants in the EFL1 gene, but the initial indication was that phenotypes may be more severe, when compared with SDS. We report a pediatric patient who presented with a metaphyseal dysplasia and was found to have biallelic variants in EFL1 on reanalysis of trio whole-exome sequencing data. The variant had not been initially reported because of the research laboratory's focus on de novo variants. Subsequent phenotyping revealed variability in her manifestations. Although her metaphyseal abnormalities were more severe than in the original reported cohort with EFL1 variants, the bone marrow abnormalities were generally mild, and there was equivocal evidence for pancreatic insufficiency. Despite the limited number of reported patients, variants in EFL1 appear to cause a broader spectrum of symptoms that overlap with those seen in SDS. Our report adds to the evidence of EFL1 being associated with an SDS-like phenotype and provides information adding to our understanding of the phenotypic variability of this disorder. Our report also highlights the value of exome data reanalysis when a diagnosis is not initially apparent
Uso de ambientes virtuales de aprendizaje en la enseñanza de la Ingeniería
El aprendizaje de la ingeniería implica la adquisición de competencias en el modelado de fenómenos y procesos, así como en la comunicación mediante el uso adecuado del lenguaje, tanto en el contexto cotidiano como en el científico y de la profesión. La visión pedagógica de la ingeniería está dirigida principalmente a la resolución de problemas. Este enfoque y la concepción de Ambientes Virtuales de Aprendizaje (AVAs) orientados a la ingeniería son apropiados para la construcción de espacios interactivos de enseñanza/aprendizaje, considerando principalmente la versatilidad determinada por la modalidad virtual. En el presente artículo se presentan experiencias llevadas a cabo en la Facultad de Ingeniería de la Universidad Nacional de Mar del Plata, se introducen las mejoras que se proponen a la plataforma Moodle con técnicas de la Minería de Datos y se presenta la potencialidad que poseen los AVA 3D para la ingeniería.Eje: Workshop Tecnología informática aplicada en educación (WTIAE)Red de Universidades con Carreras en Informática (RedUNCI
Modelos de desarrollo de serious games: las analíticas de aprendizaje e inteligencia artificial
En este trabajo se presenta el proyecto de investigación, continuación de uno anterior denominado: “El Proceso de Desarrollo de Serious Games. Modelos, herramientas y Analíticas de Aprendizaje”, en el cual se amplía el alcance de la interacción entre el jugador (estudiante) y el Serious Game (SG), aportando una retroalimentación basada en las métricas que arrojan las Analíticas de Aprendizaje (AA) del desempeño logrado durante el desarrollo del juego. Con la posibilidad de procesar grandes volúmenes de datos, los sistemas de recomendación, son un enfoque práctico para proporcionar la información más adecuada al usuario en función de su comportamiento y contexto.
Este proyecto tiene como objetivo construir un marco teórico-práctico para la incorporación de recomendaciones en un SG a partir de las métricas de evaluación obtenidas de las AA.
Nuestra propuesta en este proyecto, se enfoca en adaptar y refinar el SG utilizando técnicas de Inteligencia Artificial y mejorando el análisis de los procesos relacionados con el aprendizaje.
Se combinan tres tendencias principales en la investigación del aprendizaje con tecnologías: Serious Games, Analíticas de Aprendizaje e Inteligencia Artificial (IA).Red de Universidades con Carreras en Informátic
Clinical Implementation of Chromosomal Microarray Analysis: Summary of 2513 Postnatal Cases
BACKGROUND: Array Comparative Genomic Hybridization (a-CGH) is a powerful molecular cytogenetic tool to detect genomic imbalances and study disease mechanism and pathogenesis. We report our experience with the clinical implementation of this high resolution human genome analysis, referred to as Chromosomal Microarray Analysis (CMA). METHODS AND FINDINGS: CMA was performed clinically on 2513 postnatal samples from patients referred with a variety of clinical phenotypes. The initial 775 samples were studied using CMA array version 4 and the remaining 1738 samples were analyzed with CMA version 5 containing expanded genomic coverage. Overall, CMA identified clinically relevant genomic imbalances in 8.5% of patients: 7.6% using V4 and 8.9% using V5. Among 117 cases referred for additional investigation of a known cytogenetically detectable rearrangement, CMA identified the majority (92.5%) of the genomic imbalances. Importantly, abnormal CMA findings were observed in 5.2% of patients (98/1872) with normal karyotypes/FISH results, and V5, with expanded genomic coverage, enabled a higher detection rate in this category than V4. For cases without cytogenetic results available, 8.0% (42/524) abnormal CMA results were detected; again, V5 demonstrated an increased ability to detect abnormality. Improved diagnostic potential of CMA is illustrated by 90 cases identified with 51 cryptic microdeletions and 39 predicted apparent reciprocal microduplications in 13 specific chromosomal regions associated with 11 known genomic disorders. In addition, CMA identified copy number variations (CNVs) of uncertain significance in 262 probands; however, parental studies usually facilitated clinical interpretation. Of these, 217 were interpreted as familial variants and 11 were determined to be de novo; the remaining 34 await parental studies to resolve the clinical significance. CONCLUSIONS: This large set of clinical results demonstrates the significantly improved sensitivity of CMA for the detection of clinically relevant genomic imbalances and highlights the need for comprehensive genetic counseling to facilitate accurate clinical correlation and interpretation
El proceso de desarrollo de serious games : Modelos, herramientas y analíticas de aprendizaje
Los serious games (SG) son aplicaciones interactivas que se concentran en el uso de los principios de diseño de juegos para otros fines no meramente lúdicos.
En este trabajo se describe el Proyecto de investigación “El proceso de desarrollo de SG. Modelos, herramientas y analíticas de aprendizaje” que será desarrollado durante los años 2020/2021 en la Facultad de Ingeniería de la Universidad Nacional de Mar del Plata (UNMDP), donde se proseguirá abordando el desarrollo de SG desde las problemáticas relativas a su aplicabilidad en diferentes dominios como defensa, salud, educación, gestión de emergencias, planificación urbana e ingeniería.
Como educadores y desarrolladores de videojuegos, la validez de los SG con respecto a sus objetivos educativos debe ser tanto mensurable como medida. La naturaleza interactiva de los videojuegos hace que la aplicación de analíticas de aprendizaje se constituya en una herramienta útil para capturar los datos de interacción de los estudiantes o aprendices con el propósito de interpretar el proceso de aprendizaje. Sin embargo, existen escasas investigaciones y normas para comunicar información entre videojuegos y sus módulos de seguimiento.
Este proyecto tiene como objetivo consolidar el proceso de análisis de la interacción de los aprendices en SG a través de la extracción de información relevante del aprendizaje y la generación de reportes que visualicen los resultados. En este proyecto se combinan dos tendencias principales en la investigación del aprendizaje con tecnologías: SG y analíticas de aprendizaje.Eje: Tecnología informática aplicada en educación.Red de Universidades con Carreras en Informátic
A case of familial isolated hemihyperplasia
BACKGROUND: Hemihyperplasia (hemihypertrophy) is defined as asymmetric body overgrowth of one or more body parts. Hemihyperplasia can be isolated or be part of well-defined syndromes such as in the case of Beckwith-Wiedemann syndrome (BWS). Isolated hemihyperplasia is usually sporadic, but a number of familial occurrences have been described. CASE PRESENTATION: We describe a Tunisian family in which three maternal cousins and their maternal grandfather present with isolated hemihyperplasia. CONCLUSIONS: The etiology of isolated hemihyperplasia is unknown although in BWS, genomic imprinting has been shown to play a role in the asymmetric overgrowth. Given the similarity between these two conditions, it is possible that both may share a common pathogenesis. We also discuss the possible genetic mechanisms leading to the production of hemihyperplasia in this family
SNP genotyping to screen for a common deletion in CHARGE Syndrome
BACKGROUND: CHARGE syndrome is a complex of birth defects including coloboma, choanal atresia, ear malformations and deafness, cardiac defects, and growth delay. We have previously hypothesized that CHARGE syndrome could be caused by unidentified genomic microdeletion, but no such deletion was detected using short tandem repeat (STR) markers spaced an average of 5 cM apart. Recently, microdeletion at 8q12 locus was reported in two patients with CHARGE, although point mutation in CHD7 on chromosome 8 was the underlying etiology in most of the affected patients. METHODS: We have extended our previous study by employing a much higher density of SNP markers (3258) with an average spacing of approximately 800 kb. These SNP markers are diallelic and, therefore, have much different properties for detection of deletions than STRs. RESULTS: A global error rate estimate was produced based on Mendelian inconsistency. One marker, rs431722 exceeded the expected frequency of inconsistencies, but no deletion could be demonstrated after retesting the 4 inconsistent pedigrees with local flanking markers or by FISH with the corresponding BAC clone. Expected deletion detection (EDD) was used to assess the coverage of specific intervals over the genome by deriving the probability of detecting a common loss of heterozygosity event over each genomic interval. This analysis estimated the fraction of unobserved deletions, taking into account the allele frequencies at the SNPs, the known marker spacing and sample size. CONCLUSIONS: The results of our genotyping indicate that more than 35% of the genome is included in regions with very low probability of a deletion of at least 2 Mb
Loss-of-function variants in CUL3 cause a syndromic neurodevelopmental disorder
Purpose De novovariants inCUL3(Cullin-3 ubiquitin ligase) have been strongly associated with neurodevelopmental disorders (NDDs), but no large case series have been reported so far. Here we aimed to collect sporadic cases carrying rare variants inCUL3,describe the genotype-phenotype correlation, and investigate the underlying pathogenic mechanism.MethodsGenetic data and detailed clinical records were collected via multi-center collaboration. Dysmorphic facial features were analyzed using GestaltMatcher. Variant effects on CUL3 protein stability were assessed using patient-derived T-cells.ResultsWe assembled a cohort of 35 individuals with heterozygousCUL3variants presenting a syndromic NDD characterized by intellectual disability with or without autistic features. Of these, 33 have loss-of-function (LoF) and two have missense variants.CUL3LoF variants in patients may affect protein stability leading to perturbations in protein homeostasis, as evidenced by decreased ubiquitin-protein conjugatesin vitro. Specifically, we show that cyclin E1 (CCNE1) and 4E-BP1 (EIF4EBP1), two prominent substrates of CUL3, fail to be targeted for proteasomal degradation in patient-derived cells.ConclusionOur study further refines the clinical and mutational spectrum ofCUL3-associated NDDs, expands the spectrum of cullin RING E3 ligase-associated neuropsychiatric disorders, and suggests haploinsufficiency via LoF variants is the predominant pathogenic mechanism
Lessons learned from additional research analyses of unsolved clinical exome cases
BACKGROUND:
Given the rarity of most single-gene Mendelian disorders, concerted efforts of data exchange between clinical and scientific communities are critical to optimize molecular diagnosis and novel disease gene discovery.
METHODS:
We designed and implemented protocols for the study of cases for which a plausible molecular diagnosis was not achieved in a clinical genomics diagnostic laboratory (i.e. unsolved clinical exomes). Such cases were recruited to a research laboratory for further analyses, in order to potentially: (1) accelerate novel disease gene discovery; (2) increase the molecular diagnostic yield of whole exome sequencing (WES); and (3) gain insight into the genetic mechanisms of disease. Pilot project data included 74 families, consisting mostly of parent-offspring trios. Analyses performed on a research basis employed both WES from additional family members and complementary bioinformatics approaches and protocols.
RESULTS:
Analysis of all possible modes of Mendelian inheritance, focusing on both single nucleotide variants (SNV) and copy number variant (CNV) alleles, yielded a likely contributory variant in 36% (27/74) of cases. If one includes candidate genes with variants identified within a single family, a potential contributory variant was identified in a total of ~51% (38/74) of cases enrolled in this pilot study. The molecular diagnosis was achieved in 30/63 trios (47.6%). Besides this, the analysis workflow yielded evidence for pathogenic variants in disease-associated genes in 4/6 singleton cases (66.6%), 1/1 multiplex family involving three affected siblings, and 3/4 (75%) quartet families. Both the analytical pipeline and the collaborative efforts between the diagnostic and research laboratories provided insights that allowed recent disease gene discoveries (PURA, TANGO2, EMC1, GNB5, ATAD3A, and MIPEP) and increased the number of novel genes, defined in this study as genes identified in more than one family (DHX30 and EBF3).
CONCLUSION:
An efficient genomics pipeline in which clinical sequencing in a diagnostic laboratory is followed by the detailed reanalysis of unsolved cases in a research environment, supplemented with WES data from additional family members, and subject to adjuvant bioinformatics analyses including relaxed variant filtering parameters in informatics pipelines, can enhance the molecular diagnostic yield and provide mechanistic insights into Mendelian disorders. Implementing these approaches requires collaborative clinical molecular diagnostic and research efforts
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