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In this paper we describe the analysis, planning, design, development, implementation and evaluation of a new online Graduate Certificate in Genomic Counselling and Variant Interpretation (GCGCVI) at The University of British Columbia (UBC). Genetic counselling is now a prerequisite for diagnostic genomic testing in many countries, demanding that genetic counselling practitioners have up-to-the-moment genomic counselling skills and knowledge. Current practitioners reported a desire for more training in this rapidly developing field: our international survey revealed substantial interest in online continuing education addressing themes such as testing and clinical bioinformatics, applied variant interpretation, evidence-based genomic counselling, and other emerging genomic topics. However, our market analysis found no post-graduate program globally that offered such training. To fill this gap, our oversight team of genetic counsellors and geneticists therefore guided development of curriculum and materials, and online learning specialists developed rigorous interactive asynchronous online graduate courses through collaboration with subject matter experts, following best practices in online learning design. Since launch in September 2020, we have gathered learner feedback using surveys and focus groups, and we have used learning analytics to understand how learners engaged with each other and with course materials. Together, these have helped us understand learner behaviour and guide the continuous process of design improvement to support the learning goals of this audience of professional learners. Our courses have been reviewed and approved by the UBC Faculty of Medicine, UBC Senate, and the Province of British Columbia Ministries of Advanced Education and Health, and assessed by the National Society of Genetic Counselors (NSGC, USA) and the Canadian Association of Genetic Counsellors (CAGC) to enable learners to receive North American continuing education credits. To date, 151 individuals from 18 countries have succeeded in one or more course and 43 have completed the entire certificate.
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Curriculum , Aprendizaje , Humanos , Genómica , Colombia Británica , ConsejoRESUMEN
BACKGROUND: The primary aim of this study was to determine if allograft function in lung transplant (LTx) recipients improves or stabilizes after laparoscopic fundoplication (LF). The secondary aim was to examine the differences in forced expiratory volume in 1 second (FEV1) before and after LF for various subgroups to identify patients who obtained a superior respiratory outcome after LF, and potential predictive factors for this outcome. METHODS: Retrospective analysis of consecutive LTx recipients undergoing LF at a single centre in Brisbane, Australia between 2004 and 2018. 149/431 proceeded to LF after clinical review and pH study. Regular pre- and post-fundoplication pulmonary function tests were collected from participants. Data were analyzed with linear mixed models, random intercept models, the Reliable Change Index (RCI), and graphical and visual analysis of the trajectory of FEV1. RESULTS: There was 100% follow-up. After Bonferroni adjustment for multiple comparison was performed, none of the models demonstrated statistical significance. The Reliable Change Index showed one patient had a significant improvement in lung function across that time period, while nine had a significant reduction. The rate of change before and after LF was similar for the 132/149 patients for whom the first and last pre- and post-LF FEV1 values were available. A subset of patients had a considerable reduction in their FEV1 in the peri-operative period (i.e., a large difference between the first measurement post-LF and the final measurement pre-LF). CONCLUSION: In the largest published cohort to date, LF performed in a high-volume center did not appear to alter the reduction in allograft function seen with time.
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Fundoplicación , Trasplante de Pulmón , Pulmón , Fundoplicación/estadística & datos numéricos , Humanos , Estudios Retrospectivos , Trasplante de Pulmón/estadística & datos numéricos , Laparoscopía , Pulmón/cirugía , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , AloinjertosRESUMEN
This report by Butler et al [...].
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PURPOSE: Genome-wide sequencing is increasingly being performed during pregnancy to identify the genetic cause of congenital anomalies. The interpretation of prenatally identified variants can be challenging and is hampered by our often limited knowledge of prenatal phenotypes. To better delineate the prenatal phenotype of Coffin-Siris syndrome (CSS), we collected clinical data from patients with a prenatal phenotype and a pathogenic variant in one of the CSS-associated genes. METHODS: Clinical data was collected through an extensive web-based survey. RESULTS: We included 44 patients with a variant in a CSS-associated gene and a prenatal phenotype; 9 of these patients have been reported before. Prenatal anomalies that were frequently observed in our cohort include hydrocephalus, agenesis of the corpus callosum, hypoplastic left heart syndrome, persistent left vena cava, diaphragmatic hernia, renal agenesis, and intrauterine growth restriction. Anal anomalies were frequently identified after birth in patients with ARID1A variants (6/14, 43%). Interestingly, pathogenic ARID1A variants were much more frequently identified in the current prenatal cohort (16/44, 36%) than in postnatal CSS cohorts (5%-9%). CONCLUSION: Our data shed new light on the prenatal phenotype of patients with pathogenic variants in CSS genes.
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Deformidades Congénitas de la Mano , Discapacidad Intelectual , Micrognatismo , Anomalías Múltiples , Proteínas Cromosómicas no Histona/genética , Cara/anomalías , Estudios de Asociación Genética , Deformidades Congénitas de la Mano/genética , Humanos , Discapacidad Intelectual/genética , Discapacidad Intelectual/patología , Micrognatismo/genética , Cuello/anomalías , FenotipoRESUMEN
With the advent of genome-wide screening methods-beginning with microarray technologies and moving onto next generation sequencing methods-the era of precision and personalized medicine was born. Genomics led the way, and its contributions are well recognized. However, "other-omics" fields have rapidly emerged and are becoming as important toward defining disease causes and exploring therapeutic benefits. In this review, we focus on the impacts of transcriptomics, and its extension-epitranscriptomics-on personalized and precision medicine efforts. There has been an explosion of transcriptomic studies particularly in the last decade, along with a growing number of recent epitranscriptomic studies in several disease areas. Here, we summarize and overview major efforts for cancer, cardiovascular disease, and neurodevelopmental disorders (including autism spectrum disorder and intellectual disability) for transcriptomics/epitranscriptomics in precision and personalized medicine. We show that leading advances are being made in both diagnostics, and in investigative and landscaping disease pathophysiological studies. As transcriptomics/epitranscriptomics screens become more widespread, it is certain that they will yield vital and transformative precision and personalized medicine contributions in ways that will significantly further genomics gains.
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Meditative practices (MPs) are an inherent lifestyle and healing practice employed in Eastern medicine and spirituality. Integrating MPs into world mainstream medicine (WMM) requires effective empirical investigation of psychophysiological impacts. Epigenomic regulation is a probable mechanism of action that is empirically assessable. Recently, WMM-styled studies have screened the epigenomic impacts of MPs with early encouraging results. This article discusses the variety of MPs extant across three major Eastern religio-spiritual-healing traditions and their integration into WMM via the lens of epigenomic modulation. MPs unanimously report positive impacts on stress-reduction pathways, known to be epigenomically sensitive. Early high-resolution assays show MPs are potent in altering the epigenome - dynamically and by inducing long-term changes. This suggests the importance of integrating MPs into WMM.
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Meditación , Terapias Mente-Cuerpo , Meditación/métodos , Religión , Taichi Chuan , Epigenómica , Bienestar PsicológicoRESUMEN
Cystic fibrosis (CF) is a devastating genetic infant-onset disease [...].
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In this interview, Dr Farah R Zahir speaks with Storm Johnson, Commissioning Editor for Epigenomics, on her work to date in the field of epigenomics, autism and intellectual disability. Dr Farah R Zahir specializes in the identification of novel genetic and epigenetic causes for neurodevelopmental diseases. Her PhD, awarded in 2011 by the University of British Columbia (UBC), resulted in the characterization of new intellectual disability (ID) syndromes, as well as discovery of several new causative genes for the disorder. She was awarded the prestigious James Miller Memorial Prize for integrating basic and clinical science in 2010. Her PhD dissertation was nominated for the Governor General's gold medal - the highest possible accolade at UBC for doctoral research work. She then completed a postdoctoral tenure in Canada's premier Michael Smith Genome Sciences Centre, where she used whole-genome-sequencing methods to comprehensively assess genetic, molecular and structural causes for ID, employing several firsts for bioinformatic data mining in the field. During her postdoctorate she won three distinguished awards and was a fellow of the Canadian Institute of Health Research, ranking in the top 2% nationally. Dr Zahir was appointed as an Assistant Professor at the Hamad Bin Khalifa University in 2016, where she led a group focused on neurogenomics and neuroepigenomics research. She was a founding member of the Precision and Genomics Medicine graduate program there. Currently she has rejoined UBC's department of Medical Genetics. Among her most significant achievements is the establishment of the novel Zahir Friedman syndrome, an intellectual disability/autism spectrum disorder syndrome that is caused by a major epigenomic regulator. Her current primary research interest is how epigenomics can be changed by environmental impacts and how these effects may be harnessed for neurodevelopmental disorders' prophylaxis and therapeutics.
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Trastorno del Espectro Autista/genética , Epigenómica , Discapacidad Intelectual/genética , Proteínas de Unión al ADN/genética , Ambiente , Interacción Gen-Ambiente , Humanos , Factores de Transcripción/genéticaRESUMEN
In 2019, we confirmed that the haploinsufficiency of CHD8 does indeed cause the novel syndromic neurodevelopmental disease we first discovered a dozen years before. Here, we report the first whole transcriptome RNAseq gene expression profiling for a patient with this new syndrome, as a preliminary exploration of potential pathophysiological mechanisms. We compared our patient transcriptome profile with that of all publicly available RNAseq datasets from human cellular models including neuronal progenitor cells, neurons and organoids. We compared differential gene expression profiles overall and conducted phenotype-informed data filtration based on the characteristic syndrome presentation. We found that concordance among differential gene expression profiles was poor across all datasets. Nevertheless, remarkably, we show that the patient blood differential gene expression profile most resembled that of the neuronal cell model, a finding that encourages further transcriptome profiling using patient blood samples. In addition, our custom phenotype-informed analyses yielded important, differentially expressed syndrome pathophysiology target genes. Finally, we note that genes dysregulated due to CHD8 heterozygous deletion are linked to known neurological as well as oncological pathways.
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Autism spectrum disorder (ASD) is a rapidly growing global pandemic that affects an estimated 1 in 59-68 children. It is a complex disease with both genetic and environmental etiologies. Due to the rapid increase in the incidence of ASD, environmental causes for ASD are gaining attention. Efforts to probe several environmental exposures that could contribute to causing ASD are underway. In this regard, this chapter is directed towards understanding prenatal exposure to key environmental factors i.e., drugs and dietary nutrients that may act via the same molecular pathway - epigenetics as a potential etiological factor for ASD. Epigenetic regulation is a molecular mechanism known to be a significant contributor to neurodevelopmental disorders. It also offers a means to explain how environmental exposures can impact genetics. We discuss the impact of maternal exposures to certain drugs, and dietary intake, on the developing fetus during pregnancy. Maternal Exposure to some drugs during gestation are associated with a higher risk of ASD, while exposure to other dietary compounds may offer promise to rescue epigenetic regulatory insults related to ASD. However, more work in this important area is still required, nevertheless preliminary research already has important implications in the understanding, prevention and treatment of ASD.
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Trastorno del Espectro Autista/inducido químicamente , Trastorno del Espectro Autista/genética , Dieta/efectos adversos , Epigénesis Genética/efectos de los fármacos , Exposición Materna/efectos adversos , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/genética , Trastorno del Espectro Autista/prevención & control , Trastorno del Espectro Autista/terapia , Femenino , Humanos , Recién Nacido , EmbarazoRESUMEN
MN1 encodes a transcriptional co-regulator without homology to other proteins, previously implicated in acute myeloid leukaemia and development of the palate. Large deletions encompassing MN1 have been reported in individuals with variable neurodevelopmental anomalies and non-specific facial features. We identified a cluster of de novo truncating mutations in MN1 in a cohort of 23 individuals with strikingly similar dysmorphic facial features, especially midface hypoplasia, and intellectual disability with severe expressive language delay. Imaging revealed an atypical form of rhombencephalosynapsis, a distinctive brain malformation characterized by partial or complete loss of the cerebellar vermis with fusion of the cerebellar hemispheres, in 8/10 individuals. Rhombencephalosynapsis has no previously known definitive genetic or environmental causes. Other frequent features included perisylvian polymicrogyria, abnormal posterior clinoid processes and persistent trigeminal artery. MN1 is encoded by only two exons. All mutations, including the recurrent variant p.Arg1295* observed in 8/21 probands, fall in the terminal exon or the extreme 3' region of exon 1, and are therefore predicted to result in escape from nonsense-mediated mRNA decay. This was confirmed in fibroblasts from three individuals. We propose that the condition described here, MN1 C-terminal truncation (MCTT) syndrome, is not due to MN1 haploinsufficiency but rather is the result of dominantly acting C-terminally truncated MN1 protein. Our data show that MN1 plays a critical role in human craniofacial and brain development, and opens the door to understanding the biological mechanisms underlying rhombencephalosynapsis.
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Anomalías Múltiples/genética , Anomalías Craneofaciales/genética , Discapacidad Intelectual/genética , Trastornos del Desarrollo del Lenguaje/genética , Malformaciones del Sistema Nervioso/genética , Transactivadores/genética , Proteínas Supresoras de Tumor/genética , Anomalías Múltiples/diagnóstico por imagen , Adolescente , Arteria Basilar/anomalías , Arteria Basilar/diagnóstico por imagen , Arterias Carótidas/anomalías , Arterias Carótidas/diagnóstico por imagen , Vermis Cerebeloso/anomalías , Vermis Cerebeloso/diagnóstico por imagen , Cerebelo/anomalías , Cerebelo/diagnóstico por imagen , Niño , Preescolar , Estudios de Cohortes , Hibridación Genómica Comparativa , Anomalías Craneofaciales/diagnóstico por imagen , Femenino , Fibroblastos/metabolismo , Humanos , Imagenología Tridimensional , Lactante , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Mutación , Malformaciones del Sistema Nervioso/diagnóstico por imagen , Degradación de ARNm Mediada por Codón sin Sentido , Polimicrogiria/diagnóstico por imagen , Polimicrogiria/genética , RNA-Seq , Reacción en Cadena en Tiempo Real de la Polimerasa , Síndrome , Tomografía Computarizada por Rayos X , Secuenciación del Exoma , Secuenciación Completa del GenomaRESUMEN
BACKGROUND: Profiling the entire genome at base pair resolution in a single test offers novel insights into disease by means of dissection of genetic contributors to phenotypic features. METHODS: We performed genome sequencing for a patient who presented with atypical hereditary sensory and autonomic neuropathy, severe epileptic encephalopathy, global developmental delay, and growth hormone deficiency. RESULTS: Assessment of the variants detected by mapped sequencing reads followed by Sanger confirmation revealed that the proband is a compound heterozygote for rare variants within RETREG1 (FAM134B), a gene associated with a recessive form of hereditary sensory and autonomic neuropathy, but not with epileptic encephalopathy or global developmental delay. Further analysis of the data also revealed a heterozygous missense variant in DNM1L, a gene previously implicated in an autosomal dominant encephalopathy, epilepsy, and global developmental delay and confirmed by Sanger sequencing to be a de novo variant not present in parental genomes. CONCLUSIONS: Our findings emphasize the importance of genome-wide sequencing in patients with a well-characterized genetic disease with atypical presentation. This approach reduces the potential for misdiagnoses.
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Dinaminas/genética , Neuropatías Hereditarias Sensoriales y Autónomas/diagnóstico , Epilepsia Generalizada/complicaciones , Epilepsia Generalizada/diagnóstico , Epilepsia Generalizada/genética , Neuropatías Hereditarias Sensoriales y Autónomas/complicaciones , Neuropatías Hereditarias Sensoriales y Autónomas/genética , Heterocigoto , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Proteínas de la Membrana/genética , Mutación Missense , LinajeRESUMEN
A decade ago, we described novel de novo submicroscopic deletions of chromosome 14q11.2 in three children with developmental delay, cognitive impairment, and similar dysmorphic features, including widely-spaced eyes, short nose with flat nasal bridge, long philtrum, prominent Cupid's bow of the upper lip, full lower lip, and auricular anomalies. We suggested that this constituted a new multiple congenital anomaly-intellectual disability syndrome due to defects in CHD8 and/or SUPT16H. The three patients in our original cohort were between 2 years and 3 years of age at the time. Here we present a fourth patient and clinical updates on our previous patients. To document the longitudinal course more fully, we integrate published reports of other patients and describe genotype-phenotype correlations among them. Children with the disorder present with developmental delay, intellectual disability, and/or autism spectrum disorder in addition to characteristic facies. Gastrointestinal and sleep problems are notable. The identification of multiple patients with the same genetic defect and characteristic clinical phenotype, confirms our suggestion that this is a syndromic disorder caused by haploinsufficiency or heterozygous loss of function of CHD8.
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Proteínas de Ciclo Celular/genética , Proteínas de Unión al ADN/genética , Discapacidad Intelectual/genética , Trastornos del Neurodesarrollo/genética , Factores de Transcripción/genética , Anomalías Múltiples/genética , Anomalías Múltiples/fisiopatología , Trastorno del Espectro Autista/genética , Trastorno del Espectro Autista/fisiopatología , Preescolar , Deleción Cromosómica , Cromosomas Humanos Par 14/genética , Facies , Femenino , Haploinsuficiencia/genética , Heterocigoto , Humanos , Discapacidad Intelectual/fisiopatología , Masculino , Megalencefalia/genética , Megalencefalia/fisiopatología , Trastornos del Neurodesarrollo/patologíaRESUMEN
ACTB encodes ß-actin, an abundant cytoskeletal housekeeping protein. In humans, postulated gain-of-function missense mutations cause Baraitser-Winter syndrome (BRWS), characterized by intellectual disability, cortical malformations, coloboma, sensorineural deafness, and typical facial features. To date, the consequences of loss-of-function ACTB mutations have not been proven conclusively. We describe heterozygous ACTB deletions and nonsense and frameshift mutations in 33 individuals with developmental delay, apparent intellectual disability, increased frequency of internal organ malformations (including those of the heart and the renal tract), growth retardation, and a recognizable facial gestalt (interrupted wavy eyebrows, dense eyelashes, wide nose, wide mouth, and a prominent chin) that is distinct from characteristics of individuals with BRWS. Strikingly, this spectrum overlaps with that of several chromatin-remodeling developmental disorders. In wild-type mouse embryos, ß-actin expression was prominent in the kidney, heart, and brain. ACTB mRNA expression levels in lymphoblastic lines and fibroblasts derived from affected individuals were decreased in comparison to those in control cells. Fibroblasts derived from an affected individual and ACTB siRNA knockdown in wild-type fibroblasts showed altered cell shape and migration, consistent with known roles of cytoplasmic ß-actin. We also demonstrate that ACTB haploinsufficiency leads to reduced cell proliferation, altered expression of cell-cycle genes, and decreased amounts of nuclear, but not cytoplasmic, ß-actin. In conclusion, we show that heterozygous loss-of-function ACTB mutations cause a distinct pleiotropic malformation syndrome with intellectual disability. Our biological studies suggest that a critically reduced amount of this protein alters cell shape, migration, proliferation, and gene expression to the detriment of brain, heart, and kidney development.
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Anomalías Múltiples/genética , Actinas/genética , Discapacidades del Desarrollo/genética , Haploinsuficiencia/genética , Actinas/biosíntesis , Adolescente , Adulto , Anciano , Animales , Ciclo Celular/genética , Proliferación Celular/genética , Niño , Preescolar , Codón sin Sentido/genética , Coloboma/genética , Facies , Femenino , Mutación del Sistema de Lectura/genética , Eliminación de Gen , Humanos , Lactante , Recién Nacido , Discapacidad Intelectual/genética , Masculino , Malformaciones del Desarrollo Cortical/genética , Ratones , Interferencia de ARN , ARN Interferente Pequeño/genética , Adulto JovenRESUMEN
BACKGROUND: Intellectual Disability (ID) is among the most common global disorders, yet etiology is unknown in ~30% of patients despite clinical assessment. Whole genome sequencing (WGS) is able to interrogate the entire genome, providing potential to diagnose idiopathic patients. METHODS: We conducted WGS on eight children with idiopathic ID and brain structural defects, and their normal parents; carrying out an extensive data analyses, using standard and discovery approaches. RESULTS: We verified de novo pathogenic single nucleotide variants (SNV) in ARID1B c.1595delG and PHF6 c.820C > T, potentially causative de novo two base indels in SQSTM1 c.115_116delinsTA and UPF1 c.1576_1577delinsA, and de novo SNVs in CACNB3 c.1289G > A, and SPRY4 c.508 T > A, of uncertain significance. We report results from a large secondary control study of 2081 exomes probing the pathogenicity of the above genes. We analyzed structural variation by four different algorithms including de novo genome assembly. We confirmed a likely contributory 165 kb de novo heterozygous 1q43 microdeletion missed by clinical microarray. The de novo assembly resulted in unmasking hidden genome instability that was missed by standard re-alignment based algorithms. We also interrogated regulatory sequence variation for known and hypothesized ID genes and present useful strategies for WGS data analyses for non-coding variation. CONCLUSION: This study provides an extensive analysis of WGS in the context of ID, providing genetic and structural insights into ID and yielding diagnoses.
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Discapacidad Intelectual/genética , Secuenciación Completa del Genoma , Niño , Genoma Humano/genética , Humanos , Mutación INDEL , Mutación Missense , Polimorfismo de Nucleótido SimpleRESUMEN
The disruption of genes involved in epigenetic regulation is well known to cause Intellectual Disability (ID). We reported a custom microarray study that interrogated among others, the epigenetic regulatory gene-class, at single exon resolution. Here we elaborate on identified intragenic CNVs involving epigenetic regulatory genes; specifically discussing those in three genes previously unreported in ID etiology-ARID2, KDM3A, and ARID4B. The changes in ARID2 and KDM3A are likely pathogenic while the ARID4B variant is uncertain. Previously, we found a CNV involving only exon 6 of the JARID2 gene occurred apparently de novo in seven patients. JARID2 is known to cause ID and other neurodevelopmental conditions. However, exon 6 of this gene encodes one of a series of repeated motifs. We therefore, investigated the impact of this variant in two cohorts and present a genotype-phenotype assessment. We find the JARID2 exon 6 CNV is benign, with a high population frequency (>14%), but nevertheless could have a contributory effect. We also present results from an interrogation of the exomes of 2,044 patients with neurocognitive phenotypes for the incidence of potentially damaging mutation in the epigenetic regulatory gene-class. This paper provides a survey of the fine-scale CNV landscape for epigenetic regulatory genes in the context of ID, describing likely pathogenic as well as benign single exon imbalances. © 2016 Wiley Periodicals, Inc.
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Variaciones en el Número de Copia de ADN , Epigénesis Genética , Exones , Regulación de la Expresión Génica , Discapacidad Intelectual/genética , Adolescente , Niño , Preescolar , Metilación de ADN , Femenino , Eliminación de Gen , Duplicación de Gen , Estudios de Asociación Genética , Genotipo , Humanos , Discapacidad Intelectual/epidemiología , Histona Demetilasas con Dominio de Jumonji/genética , Masculino , Mutación , Fenotipo , Complejo Represivo Polycomb 2/genética , Vigilancia de la PoblaciónRESUMEN
Diagnosing constitutional pathogenic copy number variants (CNVs) requires detecting submicroscopic segmental chromosomal imbalances. The Affymetrix GeneChip mapping array was one of the initial microarray platforms used to measure duplication and deletion of genetic material in DNA samples. Unlike oligonucleotide microarrays from NimbleGen and Agilent, developed around the same time to infer copy number status for the DNA sequence covered by the probe, the Affymetrix GeneChip system used 25-mer oligonucleotide probes designed to interrogate SNPs. Thus, it was possible to use the Affymetrix 'SNP chips' to both identify SNPs and to identify copy number status. Affymetrix now offers the CytoScan microarray platforms, which are optimized for copy-number analyses, and provides accompanying software. They also offer several other microarray platforms suitable for copy-number analyses. Here we discuss the application of the CytoScan high-density (HD) platform for the detection of genomic imbalance. We provide an overview of the sequence of computational analyses involved in identifying pathogenic CNVs and highlight important parameters for consideration in assessing the pathogenicity of a detected CNV.
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Variaciones en el Número de Copia de ADN/genética , Dosificación de Gen , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Alelos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Patrón de Herencia/genética , Pérdida de Heterocigocidad , Mosaicismo , Relación Señal-Ruido , Disomía Uniparental/diagnósticoRESUMEN
PURPOSE: The endoplasmic reticulum-associated degradation pathway is responsible for the translocation of misfolded proteins across the endoplasmic reticulum membrane into the cytosol for subsequent degradation by the proteasome. To define the phenotype associated with a novel inherited disorder of cytosolic endoplasmic reticulum-associated degradation pathway dysfunction, we studied a series of eight patients with deficiency of N-glycanase 1. METHODS: Whole-genome, whole-exome, or standard Sanger sequencing techniques were employed. Retrospective chart reviews were performed in order to obtain clinical data. RESULTS: All patients had global developmental delay, a movement disorder, and hypotonia. Other common findings included hypolacrima or alacrima (7/8), elevated liver transaminases (6/7), microcephaly (6/8), diminished reflexes (6/8), hepatocyte cytoplasmic storage material or vacuolization (5/6), and seizures (4/8). The nonsense mutation c.1201A>T (p.R401X) was the most common deleterious allele. CONCLUSION: NGLY1 deficiency is a novel autosomal recessive disorder of the endoplasmic reticulum-associated degradation pathway associated with neurological dysfunction, abnormal tear production, and liver disease. The majority of patients detected to date carry a specific nonsense mutation that appears to be associated with severe disease. The phenotypic spectrum is likely to enlarge as cases with a broader range of mutations are detected.
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Anomalías Múltiples/genética , Degradación Asociada con el Retículo Endoplásmico/genética , Mutación , Péptido-N4-(N-acetil-beta-glucosaminil) Asparagina Amidasa/genética , Transducción de Señal/genética , Anomalías Múltiples/enzimología , Anomalías Múltiples/patología , Adolescente , Preescolar , Discapacidades del Desarrollo/patología , Exoma/genética , Salud de la Familia , Resultado Fatal , Femenino , Estudio de Asociación del Genoma Completo/métodos , Humanos , Lactante , Masculino , Microcefalia/patología , Trastornos del Movimiento/patología , Hipotonía Muscular/patología , Linaje , Péptido-N4-(N-acetil-beta-glucosaminil) Asparagina Amidasa/deficiencia , Estudios Retrospectivos , Convulsiones/patología , Análisis de Secuencia de ADN/métodos , Adulto JovenRESUMEN
Intellectual disability affects about 3% of individuals globally, withâ¼50% idiopathic. We designed an exonic-resolution array targeting all known submicroscopic chromosomal intellectual disability syndrome loci, causative genes for intellectual disability, and potential candidate genes, all genes encoding glutamate receptors and epigenetic regulators. Using this platform, we performed chromosomal microarray analysis on 165 intellectual disability trios (affected child and both normal parents). We identified and independently validated 36 de novo copy-number changes in 32 trios. In all, 67% of the validated events were intragenic, involving only exon 1 (which includes the promoter sequence according to our design), exon 1 and adjacent exons, or one or more exons excluding exon 1. Seventeen of the 36 copy-number variants involve genes known to cause intellectual disability. Eleven of these, including seven intragenic variants, are clearly pathogenic (involving STXBP1, SHANK3 (3 patients), IL1RAPL1, UBE2A, NRXN1, MEF2C, CHD7, 15q24 and 9p24 microdeletion), two are likely pathogenic (PI4KA, DCX), two are unlikely to be pathogenic (GRIK2, FREM2), and two are unclear (ARID1B, 15q22 microdeletion). Twelve individuals with genomic imbalances identified by our array were tested with a clinical microarray, and six had a normal result. We identified de novo copy-number variants within genes not previously implicated in intellectual disability and uncovered pathogenic variation of known intellectual disability genes below the detection limit of standard clinical diagnostic chromosomal microarray analysis.