151
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Suliman R, Ben-David E, Shifman S. Chromatin regulators, phenotypic robustness, and autism risk. Front Genet 2014; 5:81. [PMID: 24782891 PMCID: PMC3989700 DOI: 10.3389/fgene.2014.00081] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 03/25/2014] [Indexed: 12/14/2022] Open
Abstract
Though extensively characterized clinically, the causes of autism spectrum disorder (ASD) remain a mystery. ASD is known to have a strong genetic basis, but it is genetically very heterogeneous. Recent studies have estimated that de novo disruptive mutations in hundreds of genes may contribute to ASD. However, it is unclear how it is possible for mutations in so many different genes to contribute to ASD. Recent findings suggest that many of the mutations disrupt genes involved in transcription regulation that are expressed prenatally in the developing brain. De novo disruptive mutations are also more frequent in girls with ASD, despite the fact that ASD is more prevalent in boys. In this paper, we hypothesize that loss of robustness may contribute to ASD. Loss of phenotypic robustness may be caused by mutations that disrupt capacitors that operate in the developing brain. This may lead to the release of cryptic genetic variation that contributes to ASD. Reduced robustness is consistent with the observed variability in expressivity and incomplete penetrance. It is also consistent with the hypothesis that the development of the female brain is more robust, and it may explain the higher rate and severity of disruptive de novo mutations in girls with ASD.
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Affiliation(s)
- Reut Suliman
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem Jerusalem, Israel
| | - Eyal Ben-David
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem Jerusalem, Israel
| | - Sagiv Shifman
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem Jerusalem, Israel
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152
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A deletion in chromosome 6q is associated with human abdominal aortic aneurysm. Clin Sci (Lond) 2014; 127:475-84. [PMID: 24708024 DOI: 10.1042/cs20130784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Current efforts to identify the genetic contribution to abdominal aortic aneurysm (AAA) have mainly focused on the assessment of germ-line variants such as single-nucleotide polymorphisms. The aim of the present study was to assess the presence of acquired chromosomal aberrations in human AAA. Microarray data of ten biopsies obtained from the site of main AAA dilatation (AAA body) and three control biopsies obtained from the macroscopically non-dilated neck of the AAA (AAA neck) were initially compared with identified chromosomal aneuploidies using the Chromosomal Aberration Region Miner (ChARM) software. A commonly deleted segment of chromosome bands 6 (q22.1-23.2) was predicted within AAA biopsies. This finding was confirmed by quantitative real-time PCR (qPCR)-based DNA copy number assessments of an independent set of six AAA body and neck biopsies which identified a fold copy number change (∆KCt) of -1±0.35, suggesting the loss of one copy of the long interspersed nucleotide element type 1 (LINE-1) mapped to chromosome 6 (q22.1-23.2). The median relative genomic content of LINE-1 DNA was also reduced in AAA body compared with AAA neck biopsies (1.540 compared with 3.159; P=0.031). A gene important for vascular homoeostasis mapped to 6q23.1, connective tissue growth factor (CTGF), was assessed and found to be significantly down-regulated within AAA bodies compared with AAA necks (0.261 compared with 0.627; P=0.031), as determined by reverse transcription qPCR using total RNA as a template. Histology demonstrated marked staining for macrophages within AAA body biopsies. We found in vitro that the median relative genomic content of LINE-1 DNA in aortic vascular smooth muscle cells (AoSMCs) exposed to pro-inflammatory medium was ~1.5 times greater than that measured in control AoSMCs exposed to non-conditioned medium (3.044 compared with 2.040; P=0.015). Our findings suggest that acquired chromosomal aberrations associated with retrotransposon propagation may predispose to sporadic AAA.
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153
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Drapeau E, Dorr NP, Elder GA, Buxbaum JD. Absence of strong strain effects in behavioral analyses of Shank3-deficient mice. Dis Model Mech 2014; 7:667-81. [PMID: 24652766 PMCID: PMC4036474 DOI: 10.1242/dmm.013821] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Haploinsufficiency of SHANK3, caused by chromosomal abnormalities or mutations that disrupt one copy of the gene, leads to a neurodevelopmental syndrome called Phelan-McDermid syndrome, symptoms of which can include absent or delayed speech, intellectual disability, neurological changes and autism spectrum disorders. The SHANK3 protein forms a key structural part of the post-synaptic density. We previously generated and characterized mice with a targeted disruption of Shank3 in which exons coding for the ankyrin-repeat domain were deleted and expression of full-length Shank3 was disrupted. We documented specific deficits in synaptic function and plasticity, along with reduced reciprocal social interactions, in Shank3 heterozygous mice. Changes in phenotype owing to a mutation at a single locus are quite frequently modulated by other loci, most dramatically when the entire genetic background is changed. In mice, each strain of laboratory mouse represents a distinct genetic background and alterations in phenotype owing to gene knockout or transgenesis are frequently different across strains, which can lead to the identification of important modifier loci. We have investigated the effect of genetic background on phenotypes of Shank3 heterozygous, knockout and wild-type mice, using C57BL/6, 129SVE and FVB/Ntac strain backgrounds. We focused on observable behaviors with the goal of carrying out subsequent analyses to identify modifier loci. Surprisingly, there were very modest strain effects over a large battery of analyses. These results indicate that behavioral phenotypes associated with Shank3 haploinsufficiency are largely strain-independent.
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Affiliation(s)
- Elodie Drapeau
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nate P Dorr
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Gregory A Elder
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA. Neurology Service, James J. Peters VA Medical Center, Bronx, NY 10468, USA
| | - Joseph D Buxbaum
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Pharmacology and Systems Therapeutics and Systems Biology Center New York, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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154
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Kim YS, State MW. Recent challenges to the psychiatric diagnostic nosology: a focus on the genetics and genomics of neurodevelopmental disorders. Int J Epidemiol 2014; 43:465-75. [PMID: 24618187 DOI: 10.1093/ije/dyu037] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Recent advances in the genetics of neurodevelopmental disorder (NDD) have demonstrated that rare mutations play a role not only in Mendelian syndromes, but in complex, common forms of NDDs as well. Strikingly, both common polymorphisms and rare variations in a single gene or genetic locus have been found to carry risk for conditions previously considered to be clinically and aetiologically distinct. Recent developments in the methods and tools available for studying complex NDDs have led to systematic and reliable genome-wide variant discovery. Both common as well as rare, and structural as well as sequence, genetic variations have been identified as contributing to NDDs. There are multiple examples in which the identical variant had been found to contribute to a wide range of formerly distinct diagnoses, including autism, schizophrenia, epilepsy, intellectual disability and language disorders. These include variations in chromosomal structure at 16p11.2, rare de novo point mutations at the gene SCN2A, and common single nucleotide polymorphisms (SNPs) mapping near loci encoding the genes ITIH3, AS3MT, CACNA1C and CACNB2. These selected examples point to the challenges to current diagnostic approaches. Widely used categorical schema have been adequate to provide an entré into molecular mechanisms of NDDs, but there is a need to develop an alternative, more biologically-relevant nosology. Thus recent advances in gene discovery in the area of NDDs are leading to a re-conceptualization of diagnostic boundaries. Findings suggest that epidemiological samples may provide important new insights into the genetics and diagnosis of NDDs and that other areas of medicine may provide useful models for developing a new diagnostic nosology, one that simultaneously integrates categorical diagnoses, biomarkers and dimensional variables.
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Affiliation(s)
- Young Shin Kim
- Yale Child Study Center, Yale University School of Medicine, New Haven, CT, USA, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA, Department of Psychiatry, Yonsei University College of Medicine, Seoul, South Korea and Department of Psychiatry, University of California, San Francisco, CA, USA
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155
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Silva IMW, Rosenfeld J, Antoniuk SA, Raskin S, Sotomaior VS. A 1.5Mb terminal deletion of 12p associated with autism spectrum disorder. Gene 2014; 542:83-6. [PMID: 24613754 DOI: 10.1016/j.gene.2014.02.058] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 02/22/2014] [Accepted: 02/27/2014] [Indexed: 11/16/2022]
Abstract
We report a patient with a terminal 12p deletion associated with autism spectrum disorder (ASD). This 12p13.33 deletion is 1.5Mb in size and encompasses 13 genes (B4GALNT3, CCDC77, ERC1, FBXL14, IQSEC3, KDM5A, LINC00942, LOC574538, NINJ2, RAD52, SLC6A12, SLC6A13 and WNK1). All previous cases reported with partial monosomy of 12p13.33 are associated with neurodevelopmental delay, and we suggest that ERC1, which encodes a regulator of neurotransmitter release, is the best gene candidate contributing to this phenotype as well as to the ASD of our patient.
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Affiliation(s)
- Isabela M W Silva
- Group for Advanced Molecular Investigation (NIMA), School of Health and Biosciences, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, Brazil
| | | | - Sergio A Antoniuk
- Pediatrics Department, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Salmo Raskin
- GENETIKA - Centro de Aconselhamento e Laboratorio de Genetica, Curitiba, Paraná, Brazil; Group for Advanced Molecular Investigation (NIMA), Graduate Program in Health Sciences, School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, Brazil
| | - Vanessa S Sotomaior
- Group for Advanced Molecular Investigation (NIMA), Graduate Program in Health Sciences, School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Paraná, Brazil.
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156
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Glutamatergic candidate genes in autism spectrum disorder: an overview. J Neural Transm (Vienna) 2014; 121:1081-106. [PMID: 24493018 DOI: 10.1007/s00702-014-1161-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 01/13/2014] [Indexed: 12/22/2022]
Abstract
Autism spectrum disorders (ASD) are neurodevelopmental disorders with early onset in childhood. Most of the risk for ASD can be explained by genetic variants that act in interaction with biological environmental risk factors. However, the architecture of the genetic components is still unclear. Genetic studies and subsequent systems biological approaches described converging functional effects of identified genes towards pathways relevant for neuronal signalling. Mouse models suggest an aberrant synaptic plasticity at the neuropathological level, which is believed to be conferred by dysregulation of long-term potentiation or depression of neuronal connections. A central pathway regulating these mechanisms is glutamatergic signalling. Here, we hypothesized that susceptibility genes for ASD are enriched for components of this pathway. To further understand the impact of ASD risk genes on the glutamatergic pathway, we performed a systematic review using the literature database "pubmed" and the "AutismKB" knowledgebase. We provide an overview of the glutamatergic system in typical brain function and development, and summarize findings from linkage, association, copy number variants, and sequencing studies in ASD to provide a comprehensive picture of the glutamatergic landscape of ASD genetics. Genetic variants associated with ASD were enriched in glutamatergic pathways, affecting receptor signalling, metabolism and transport. Furthermore, in genetically modified mouse models for ASD, pharmacological compounds acting on ionotropic or metabotropic receptor activity are able to rescue ASD reminscent phenotypes. We conclude that glutamatergic genetic risk factors for ASD show a complex pattern and further studies are needed to fully understand its mechanisms, before translation of findings into clinical applications and individualized treatment approaches will be possible.
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157
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Treating the whole person with autism: the proceedings of the Autism Speaks National Autism Conference. Curr Probl Pediatr Adolesc Health Care 2014; 44:26-47. [PMID: 24491508 DOI: 10.1016/j.cppeds.2013.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 12/03/2013] [Indexed: 12/12/2022]
Abstract
The identification of autism spectrum disorders has increased dramatically over the past decade, with the latest estimates indicating prevalence as high as 1 in 54 boys. There is greater awareness of medical conditions that co-occur with autism and expansion of treatment options. Closer scrutiny has led to refinement of the diagnostic criteria, and there have been advances in genetics examining potential causal factors. Transition to adulthood is an area of growing concern, and professionals and families require guidance on this issue. This article summarizes the proceedings of the Autism Speaks conference on Treating the Whole Person with Autism: Care across the Lifespan. The conference was organized with the intent of providing a forum for both families and professionals to learn about the most current research in the field. Dr. Sue Swedo provides important background information regarding the changes in the diagnostic criteria for autism spectrum disorders. She particularly deals with the concerns of individuals and families that their autism diagnosis may change. Recommendations for genetic testing and its interpretation are provided by Dr. David Miller. His discussion helps make sense of the utility of genetic testing for ASD, along with demonstration of the complexity of determining which genetic factors are doing what and through which pathways. Dr. Jeremy Veenstra-VanderWeele provides useful background information on how medicines are initially identified and for what purpose and goes on to describe the present and future treatments in pharmacology. Medical issues are addressed by Dr. Paul Carbone, especially the coordination of comprehensive services through the medical home model of care. Dr. Julie Lounds Taylor concludes with guidance on preparation for adulthood, a topic of great importance to families as their child matures and for the professionals who will help guide this transition.
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158
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Roberts JL, Hovanes K, Dasouki M, Manzardo AM, Butler MG. Chromosomal microarray analysis of consecutive individuals with autism spectrum disorders or learning disability presenting for genetic services. Gene 2014; 535:70-8. [PMID: 24188901 PMCID: PMC4423794 DOI: 10.1016/j.gene.2013.10.020] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/26/2013] [Accepted: 10/10/2013] [Indexed: 01/15/2023]
Abstract
Chromosomal microarray analysis is now commonly used in clinical practice to identify copy number variants (CNVs) in the human genome. We report our experience with the use of the 105 K and 180K oligonucleotide microarrays in 215 consecutive patients referred with either autism or autism spectrum disorders (ASD) or developmental delay/learning disability for genetic services at the University of Kansas Medical Center during the past 4 years (2009-2012). Of the 215 patients [140 males and 75 females (male/female ratio=1.87); 65 with ASD and 150 with learning disability], abnormal microarray results were seen in 45 individuals (21%) with a total of 49 CNVs. Of these findings, 32 represented a known diagnostic CNV contributing to the clinical presentation and 17 represented non-diagnostic CNVs (variants of unknown significance). Thirteen patients with ASD had a total of 14 CNVs, 6 CNVs recognized as diagnostic and 8 as non-diagnostic. The most common chromosome involved in the ASD group was chromosome 15. For those with a learning disability, 32 patients had a total of 35 CNVs. Twenty-six of the 35 CNVs were classified as a known diagnostic CNV, usually a deletion (n=20). Nine CNVs were classified as an unknown non-diagnostic CNV, usually a duplication (n=8). For the learning disability subgroup, chromosomes 2 and 22 were most involved. Thirteen out of 65 patients (20%) with ASD had a CNV compared with 32 out of 150 patients (21%) with a learning disability. The frequency of chromosomal microarray abnormalities compared by subject group or gender was not statistically different. A higher percentage of individuals with a learning disability had clinical findings of seizures, dysmorphic features and microcephaly, but not statistically significant. While both groups contained more males than females, a significantly higher percentage of males were present in the ASD group.
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Key Words
- A2BP1
- ACADL
- ACOXL
- ADIPOQ
- ALS2 chromosome region gene 8
- ALS2CR8
- ANKRD11
- ANOVA
- ASD
- Autism spectrum disorders (ASD)
- BAC
- BCL2-like 11 gene
- BCL2L11
- CACNA1C
- CHRNA7
- CNV
- COBL
- CT
- Chromosomal microarray analysis
- Copy number variant (CNV)
- DLG1
- DLG4
- DNA
- Developmental delay
- EEF1B2
- EEG
- F-box only 45 gene
- FAM117B
- FAT tumor suppressor 1 gene
- FAT1
- FBXO45
- FISH
- FXR2
- FZD5
- GALR1
- GATA zinc finger domain-containing protein 2B gene
- GATAD2B
- GDNF-inducible zinc finger protein 1 gene
- GZF1
- HAX1
- HCLS1-associated protein X1 gene
- HDAC
- IDH1
- IL1RAPL1
- ITPR1
- KLF7
- KNG1
- LINS
- LMNA
- Learning disability
- MAP2
- MBP
- MRPL19
- MYL1
- NADH-ubiquinone oxidoreductase Fe-S protein 1 gene
- NDUFS1
- NLGN2
- NPHP1
- NRXN1
- PAK2
- PARK2
- PMP22
- POLG
- PRPF8
- PTEN
- PTH2R
- RPE
- SACS
- SD
- SH2B adaptor protein 1 gene
- SH2B1
- SH3 and multiple ankyrin repeat domains 3 gene
- SHANK3
- SHOX
- SMARCA4
- STAG2
- SUMF1
- SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member gene
- TRAPPC2
- UCSC
- USP6
- University of California, Santa Cruz
- X-linked inhibitor of apoptosis gene
- XIAP
- YWHAE
- ZNF407
- aCGH
- acyl-coA dehydrogenase, long chain gene
- acyl-coA oxidase-like gene
- adipocyte-, C1q-, and collagen domain containing gene
- analysis of variance
- ankyrin repeat domain-containing protein 11 gene
- array comparative genomic hybridization
- ataxin 2-binding protein 1 gene
- autism spectrum disorder
- bacterial artificial chromosome
- calcium channel, voltage dependent, L-type, alpha 1C subunit gene
- cholinergic receptor, neuronal nicotinic, alpha polypeptide 7 gene
- computed tomography
- copy number variant
- cordon-bleu gene
- deoxyribonucleic acid
- discs, large homolog 1 gene
- discs, large homolog 4 gene
- electroencephalogram
- eukaryotic translation elongation factor 1, beta-2 gene
- family with sequence similarity 117, member B gene
- fluorescence in situ hybridization
- fragile X mental retardation, autosomal homolog 2 gene
- frizzled 5 gene
- galanin receptor 1 gene
- histone deacetylase gene
- inositol 1,4,5-triphosphate receptor, type 1 gene
- interleukin 1 receptor accessory protein-like 1 gene
- isocitrate dehydrogenase 1 gene
- kininogen 1 gene
- kruppel-like factor 7 gene
- lamin A gene
- lines homolog gene
- microtubule-associated protein 2 gene
- mitochondrial ribosomal protein L19 gene
- myelin basic protein gene
- myosin, light peptide 1 gene
- nephrocystin 1 gene
- neurexin 1 gene
- neuroligin 2 gene
- parathyroid hormone receptor 2 gene
- parkin gene
- peripheral myelin protein 22 gene
- phosphatase and tensin homolog gene
- polymerase gamma gene
- precursor mRNA-processing factor 8 gene
- protein-activated kinase 2 gene
- ribulose 5-phosphate 3-epimerase gene
- sacsin gene
- short stature homeobox gene
- standard deviation
- stromal antigen 2 gene
- sulfatase-modifying factor 1 gene
- tracking protein particle complex, subunit 2 gene
- tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, epsilon isoform gene
- ubiquitin-specific protease 6 gene
- zinc finger protein 407 gene
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Affiliation(s)
- Jennifer L Roberts
- Departments of Psychiatry, Behavioral Sciences and Pediatrics, The University of Kansas, Medical Center, Kansas City, KS, USA
| | | | - Majed Dasouki
- Department of Neurology, The University of Kansas Medical Center, Kansas City, KS, USA; King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ann M Manzardo
- Departments of Psychiatry, Behavioral Sciences and Pediatrics, The University of Kansas, Medical Center, Kansas City, KS, USA
| | - Merlin G Butler
- Departments of Psychiatry, Behavioral Sciences and Pediatrics, The University of Kansas, Medical Center, Kansas City, KS, USA.
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159
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Rosti RO, Sadek AA, Vaux KK, Gleeson JG. The genetic landscape of autism spectrum disorders. Dev Med Child Neurol 2014; 56:12-8. [PMID: 24116704 DOI: 10.1111/dmcn.12278] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/22/2013] [Indexed: 12/13/2022]
Abstract
Autism spectrum disorders (ASDs) are a group of heterogeneous neurodevelopmental disorders that show impaired communication and socialization, restricted interests, and stereotypical behavioral patterns. Recent advances in molecular medicine and high throughput screenings, such as array comparative genomic hybridization (CGH) and exome and whole genome sequencing, have revealed both novel insights and new questions about the nature of this spectrum of disorders. What has emerged is a better understanding about the genetic architecture of various genetic subtypes of ASD and correlations of genetic mutations with specific autism subtypes. Based on this new information, we outline a strategy for advancing diagnosis, prognosis, and counseling for patients and families.
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Affiliation(s)
- Rasim O Rosti
- Department of Neurosciences and Pediatrics, Howard Hughes Medical Institute, University of California, San Diego, CA, USA
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160
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Abstract
Autism spectrum disorder (ASD) is a biologically based neurodevelopmental disability characterized by qualitative and persistent deficits in social communication and social interaction and by the presence of restricted, repetitive, and stereotyped patterns of behavior. Symptoms must be present in early childhood and they must limit and impair everyday functioning. There is an increased prevalence of epilepsy and/or epileptiform electroencephalography (EEG) abnormalities in children with ASD. It is estimated that approximately one-third of children and adolescents with ASD experience seizures, but the relationship between epilepsy and autism is controversial. This article reviews the types of seizures associated with ASD, the EEG findings, and current treatment strategies. The article also describes syndromes associated with the autism phenotype and epilepsy.
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161
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Parellada M, Penzol MJ, Pina L, Moreno C, González-Vioque E, Zalsman G, Arango C. The neurobiology of autism spectrum disorders. Eur Psychiatry 2013; 29:11-9. [PMID: 24275633 DOI: 10.1016/j.eurpsy.2013.02.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 02/20/2013] [Indexed: 01/22/2023] Open
Abstract
Data is progressively and robustly accumulating regarding the biological basis of autism. Autism spectrum disorders (ASD) are currently considered a group of neurodevelopmental disorders with onset very early in life and a complex, heterogeneous, multifactorial aetiology. A comprehensive search of the last five years of the Medline database was conducted in order to summarize recent evidence on the neurobiological bases of autism. The main findings on genetic influence, neuropathology, neurostructure and brain networks are summarized. In addition, findings from peripheral samples of subjects with autism and animal models, which show immune, oxidative, mitochondrial dysregulations, are reported. Then, other biomarkers from very different systems associated with autism are reported. Finally, an attempt is made to try and integrate the available evidence, which points to a oligogenetic, multifactorial aetiology that converges in an aberrant micro-organization of the cortex, with abnormal functioning of the synapses and abnormalities in very general physiological pathways (such as inflammatory, immune and redox systems).
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Affiliation(s)
- M Parellada
- Child and Adolescent Psychiatry Department, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, Hospital General Universitario Gregorio Marañón, CIBERSAM, Ibiza 43, 28009 Madrid, Spain.
| | - M J Penzol
- Child and Adolescent Psychiatry Department, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, Hospital General Universitario Gregorio Marañón, CIBERSAM, Ibiza 43, 28009 Madrid, Spain
| | - L Pina
- Child and Adolescent Psychiatry Department, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, Hospital General Universitario Gregorio Marañón, CIBERSAM, Ibiza 43, 28009 Madrid, Spain
| | - C Moreno
- Child and Adolescent Psychiatry Department, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, Hospital General Universitario Gregorio Marañón, CIBERSAM, Ibiza 43, 28009 Madrid, Spain
| | - E González-Vioque
- Child and Adolescent Psychiatry Department, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, Hospital General Universitario Gregorio Marañón, CIBERSAM, Ibiza 43, 28009 Madrid, Spain
| | - G Zalsman
- Child and Adolescent Psychiatry, Geha Hospital, Petach Tiqva, 49100 Tel Aviv, Israel
| | - C Arango
- Child and Adolescent Psychiatry Department, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, Hospital General Universitario Gregorio Marañón, CIBERSAM, Ibiza 43, 28009 Madrid, Spain
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162
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Cochran DM, Dvir Y, Frazier JA. "Autism-plus" spectrum disorders: intersection with psychosis and the schizophrenia spectrum. Child Adolesc Psychiatr Clin N Am 2013; 22:609-27. [PMID: 24012076 DOI: 10.1016/j.chc.2013.04.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Patients are often encountered clinically who have autism spectrum disorders (ASD) and also have symptoms suggestive of a comorbid psychotic disorder. A careful assessment for the presence of comorbid disorders is important. However, the core deficits seen in ASD, in social reciprocity, communication, and restricted behaviors and interests, can be mistaken for psychosis. Also, there is a subset of patients who present with a complex neurodevelopmental disorder with impairments that cross diagnostic categories. This article reviews the connections between ASD and psychosis, and highlights the key points to consider in patients who present with these "autism-plus" disorders.
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Affiliation(s)
- David M Cochran
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of Massachusetts Medical School, Biotech One, Suite 100, 365 Plantation Street, Worcester, MA 01605, USA.
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163
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Benjamin S, Lauterbach MD, Stanislawski AL. Congenital and acquired disorders presenting as psychosis in children and young adults. Child Adolesc Psychiatr Clin N Am 2013; 22:581-608. [PMID: 24012075 DOI: 10.1016/j.chc.2013.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A review of the published literature found 60 congenital and acquired disorders with symptoms that include psychosis in youth. The prevalence, workup, genetics, and associated neuropsychiatric features of each disorder are described. Eighteen disorders (30%) have distinct phenotypes (doorway diagnoses); 18 disorders (30%) are associated with intellectual disability; and 43 disorders (72%) have prominent neurologic signs. Thirty-one disorders (52%) can present without such distinct characteristics, and are thus more easily overlooked. A systematic and cost-effective differential diagnostic approach based on estimated prevalence and most prominent associated signs is recommended.
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Affiliation(s)
- Sheldon Benjamin
- Departments of Psychiatry and Neurology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
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164
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Shea L, Newschaffer CJ, Xie M, Myers SM, Mandell DS. Genetic testing and genetic counseling among Medicaid-enrolled children with autism spectrum disorder in 2001 and 2007. Hum Genet 2013; 133:111-6. [PMID: 24036677 DOI: 10.1007/s00439-013-1362-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 09/08/2013] [Indexed: 11/24/2022]
Abstract
The rise in the prevalence of autism spectrum disorder (ASD) has resulted in increased efforts to understand the causes of this complex set of disorders that emerge early in childhood. Although research in this area is underway and yielding useful, but complex information about ASD, guidelines for the use of genetic testing and counseling among children with ASD conflict. The purpose of this study was to determine the frequency of use of genetic testing and counseling before the widespread implementation of clinical chromosomal microarray (CMA) to establish a baseline for the use of both services and to investigate potential disparities in the use of both services among children with ASD. We found that about two-thirds of children with ASD received genetic testing or counseling and the use of both services is increasing with time, even in the pre-CMA era. Being female and having a comorbid intellectual disability diagnosis both increased the likelihood of receiving genetic testing and genetic counseling. Initial discrepancies in the use of both services based on race/ethnicity suggest that troubling disparities observed in other services delivered to children with ASD and other mental health disorders persist in genetic testing and counseling as well. These results should incentivize further investigation of the impact of genetic testing and counseling on children with ASD and their families, and should drive efforts to explore and confront disparities in the delivery of these services, particularly with the advancing scientific research on this topic.
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Affiliation(s)
- Lindsay Shea
- A.J. Drexel Autism Institute, Drexel University, 3020 Market St., Suite 560, Philadelphia, PA, 19104-3734, USA,
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165
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Carbone PS. Moving from research to practice in the primary care of children with autism spectrum disorders. Acad Pediatr 2013; 13:390-9. [PMID: 24011743 DOI: 10.1016/j.acap.2013.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/27/2013] [Accepted: 04/05/2013] [Indexed: 10/26/2022]
Abstract
Autism spectrum disorders (ASD), once thought rare, are now commonly encountered in clinical practice. Academic pediatricians may be expected to teach medical students and pediatric residents about ASD, but most likely received limited exposure to ASD during their training. In recent years, research that informs the clinical guidance provided to pediatricians regarding surveillance, screening, and ongoing management of children with ASD has accelerated. By 24 months of age, children with ASD exhibit delays across multiple domains of development, yet the diagnosis is frequently made much later. Careful developmental surveillance lowers the age of identification of children with ASD. Several screening tools appropriate for use in primary care settings can aid in early identification. Improved surveillance and screening is of benefit because early intensive behavioral intervention has the potential to improve the developmental trajectory of children with ASD. Providing appropriate medical care for children with ASD improves both child and family outcomes. Recent research regarding sleep disturbances, gastrointestinal problems, and epilepsy in children with ASD has led to clinical pathways to evaluate and address these issues within the context of primary care. By being aware of and disseminating these research findings, academic pediatricians can help future and current clinicians improve the care of children with ASD.
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Affiliation(s)
- Paul S Carbone
- Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, Utah.
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166
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Shashi V, McConkie-Rosell A, Rosell B, Schoch K, Vellore K, McDonald M, Jiang YH, Xie P, Need A, Goldstein DB, Goldstein DG. The utility of the traditional medical genetics diagnostic evaluation in the context of next-generation sequencing for undiagnosed genetic disorders. Genet Med 2013; 16:176-82. [PMID: 23928913 DOI: 10.1038/gim.2013.99] [Citation(s) in RCA: 200] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/11/2013] [Indexed: 12/16/2022] Open
Abstract
PURPOSE The purpose of this study was to assess the diagnostic yield of the traditional, comprehensive clinical evaluation and targeted genetic testing, within a general genetics clinic. These data are critically needed to develop clinically and economically grounded diagnostic algorithms that consider presenting phenotype, traditional genetics testing, and the emerging role of next-generation sequencing (whole-exome/genome sequencing). METHODS We retrospectively analyzed a cohort of 500 unselected consecutive patients who received traditional genetic diagnostic evaluations at a tertiary medical center. We calculated the diagnosis rate, number of visits to diagnosis, genetic tests, and the cost of testing. RESULTS Thirty-nine patients were determined to not have a genetic disorder; 212 of the remaining 461 (46%) received a genetic diagnosis, and 72% of these were diagnosed on the first visit. The cost per subsequent successful genetic diagnosis was estimated at $25,000. CONCLUSION Almost half of the patients were diagnosed using the traditional approach, most at the initial visit. For those remaining undiagnosed, next-generation sequencing may be clinically and economically beneficial. Estimating a 50% success rate for next-generation sequencing in undiagnosed genetic disorders, its application after the first clinical visit could result in a higher rate of genetic diagnosis at a considerable cost savings per successful diagnosis.
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Affiliation(s)
- Vandana Shashi
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Allyn McConkie-Rosell
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Bruce Rosell
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Kelly Schoch
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Kasturi Vellore
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Marie McDonald
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Yong-Hui Jiang
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Pingxing Xie
- Center for Human Genome Variation, Duke University Medical Center, Durham, North Carolina, USA
| | - Anna Need
- Center for Human Genome Variation, Duke University Medical Center, Durham, North Carolina, USA
| | | | - David G Goldstein
- Center for Human Genome Variation, Duke University Medical Center, Durham, North Carolina, USA
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167
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Affiliation(s)
- Amira T. Masri
- Division of Child Neurology, Department of Pediatrics, Faculty of Medicine, University of Jordan, Amman, Jordan
| | - Najati Al Suluh
- Division of Child Neurology, Department of Pediatrics, Faculty of Medicine, University of Jordan, Amman, Jordan
| | - Ramzi Nasir
- Department of Developmental Behavioral Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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168
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Trottier M, Roberts W, Drmic I, Scherer SW, Weksberg R, Cytrynbaum C, Chitayat D, Shuman C, Miller FA. Parents' perspectives on participating in genetic research in autism. J Autism Dev Disord 2013; 43:556-68. [PMID: 22782649 DOI: 10.1007/s10803-012-1592-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Genetic research in autism depends on the willingness of individuals with autism to participate; thus, there is a duty to assess participants' needs in the research process. We report on families' motives and expectations related to their participation in autism genetic research. Respondents valued having a genetic result, as it alleviates guilt, promotes awareness, and may be used to tailor interventions and for family planning. The act of participating was distinctly significant, as it provided personal control, a connection to autism experts, networking with families, and hope for the future. The results of this study highlight complex factors involved in families' decisions to participate in autism genetic research and provide points to consider for this population of research participants.
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Affiliation(s)
- Magan Trottier
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada
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169
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Braeutigam S. Magnetoencephalography: fundamentals and established and emerging clinical applications in radiology. ISRN RADIOLOGY 2013; 2013:529463. [PMID: 24967282 PMCID: PMC4045536 DOI: 10.5402/2013/529463] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 07/03/2013] [Indexed: 12/17/2022]
Abstract
Magnetoencephalography is a noninvasive, fast, and patient friendly technique for recording brain activity. It is increasingly available and is regarded as one of the most modern imaging tools available to radiologists. The dominant clinical use of this technology currently centers on two, partly overlapping areas, namely, localizing the regions from which epileptic seizures originate, and identifying regions of normal brain function in patients preparing to undergo brain surgery. As a consequence, many radiologists may not yet be familiar with this technique. This review provides an introduction to magnetoencephalography, discusses relevant analytical techniques, and presents recent developments in established and emerging clinical applications such as pervasive developmental disorders. Although the role of magnetoencephalography in diagnosis, prognosis, and patient treatment is still limited, it is argued that this technology is exquisitely capable of contributing indispensable information about brain dynamics not easily obtained with other modalities. This, it is believed, will make this technology an important clinical tool for a wide range of disorders in the future.
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Affiliation(s)
- Sven Braeutigam
- Oxford Centre for Human Brain Activity, Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, UK
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170
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Jiang YH, Yuen R, Jin X, Wang M, Chen N, Wu X, Ju J, Mei J, Shi Y, He M, Wang G, Liang J, Wang Z, Cao D, Carter M, Chrysler C, Drmic I, Howe J, Lau L, Marshall C, Merico D, Nalpathamkalam T, Thiruvahindrapuram B, Thompson A, Uddin M, Walker S, Luo J, Anagnostou E, Zwaigenbaum L, Ring R, Wang J, Lajonchere C, Wang J, Shih A, Szatmari P, Yang H, Dawson G, Li Y, Scherer S. Detection of clinically relevant genetic variants in autism spectrum disorder by whole-genome sequencing. Am J Hum Genet 2013; 93:249-63. [PMID: 23849776 DOI: 10.1016/j.ajhg.2013.06.012] [Citation(s) in RCA: 335] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 05/13/2013] [Accepted: 06/12/2013] [Indexed: 01/08/2023] Open
Abstract
Autism Spectrum Disorder (ASD) demonstrates high heritability and familial clustering, yet the genetic causes remain only partially understood as a result of extensive clinical and genomic heterogeneity. Whole-genome sequencing (WGS) shows promise as a tool for identifying ASD risk genes as well as unreported mutations in known loci, but an assessment of its full utility in an ASD group has not been performed. We used WGS to examine 32 families with ASD to detect de novo or rare inherited genetic variants predicted to be deleterious (loss-of-function and damaging missense mutations). Among ASD probands, we identified deleterious de novo mutations in six of 32 (19%) families and X-linked or autosomal inherited alterations in ten of 32 (31%) families (some had combinations of mutations). The proportion of families identified with such putative mutations was larger than has been previously reported; this yield was in part due to the comprehensive and uniform coverage afforded by WGS. Deleterious variants were found in four unrecognized, nine known, and eight candidate ASD risk genes. Examples include CAPRIN1 and AFF2 (both linked to FMR1, which is involved in fragile X syndrome), VIP (involved in social-cognitive deficits), and other genes such as SCN2A and KCNQ2 (linked to epilepsy), NRXN1, and CHD7, which causes ASD-associated CHARGE syndrome. Taken together, these results suggest that WGS and thorough bioinformatic analyses for de novo and rare inherited mutations will improve the detection of genetic variants likely to be associated with ASD or its accompanying clinical symptoms.
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171
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Costain G, Lionel AC, Merico D, Forsythe P, Russell K, Lowther C, Yuen T, Husted J, Stavropoulos DJ, Speevak M, Chow EWC, Marshall CR, Scherer SW, Bassett AS. Pathogenic rare copy number variants in community-based schizophrenia suggest a potential role for clinical microarrays. Hum Mol Genet 2013; 22:4485-501. [PMID: 23813976 DOI: 10.1093/hmg/ddt297] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Individually rare, large copy number variants (CNVs) contribute to genetic vulnerability for schizophrenia. Unresolved questions remain, however, regarding the anticipated yield of clinical microarray testing in schizophrenia. Using high-resolution genome-wide microarrays and rigorous methods, we investigated rare CNVs in a prospectively recruited community-based cohort of 459 unrelated adults with schizophrenia and estimated the minimum prevalence of clinically significant CNVs that would be detectable on a clinical microarray. A blinded review by two independent clinical cytogenetic laboratory directors of all large (>500 kb) rare CNVs in cases and well-matched controls showed that those deemed to be clinically significant were highly enriched in schizophrenia (16.4-fold increase, P < 0.0001). In a single community catchment area, the prevalence of individuals with these CNVs was 8.1%. Rare 1.7 Mb CNVs at 2q13 were found to be significantly associated with schizophrenia for the first time, compared with the prevalence in 23 838 population-based controls (42.9-fold increase, P = 0.0002). Additional novel findings that will facilitate the future clinical interpretation of smaller CNVs in schizophrenia include: (i) a greater proportion of individuals with two or more rare exonic CNVs >10 kb in size (1.5-fold increase, P = 0.0109) in schizophrenia; (ii) the systematic discovery of new candidate genes for schizophrenia; and, (iii) functional gene enrichment mapping highlighting a differential impact in schizophrenia of rare exonic deletions involving diverse functions, including neurodevelopmental and synaptic processes (4.7-fold increase, P = 0.0060). These findings suggest consideration of a potential role for clinical microarray testing in schizophrenia, as is now the suggested standard of care for related developmental disorders like autism.
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Affiliation(s)
- Gregory Costain
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, ON, Canada M5S 2S1
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172
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Menashe I, Larsen EC, Banerjee-Basu S. Prioritization of Copy Number Variation Loci Associated with Autism from AutDB-An Integrative Multi-Study Genetic Database. PLoS One 2013; 8:e66707. [PMID: 23825557 PMCID: PMC3688962 DOI: 10.1371/journal.pone.0066707] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Accepted: 05/13/2013] [Indexed: 12/20/2022] Open
Abstract
Copy number variants (CNVs) are thought to play an important role in the predisposition to autism spectrum disorder (ASD). However, their relatively low frequency and widespread genomic distribution complicates their accurate characterization and utilization for clinical genetics purposes. Here we present a comprehensive analysis of multi-study, genome-wide CNV data from AutDB (http://mindspec.org/autdb.html), a genetic database that accommodates detailed annotations of published scientific reports of CNVs identified in ASD individuals. Overall, we evaluated 4,926 CNVs in 2,373 ASD subjects from 48 scientific reports, encompassing ∼2.12×109 bp of genomic data. Remarkable variation was seen in CNV size, with duplications being significantly larger than deletions, (P = 3×10−105; Wilcoxon rank sum test). Examination of the CNV burden across the genome revealed 11 loci with a significant excess of CNVs among ASD subjects (P<7×10−7). Altogether, these loci covered 15,610 kb of the genome and contained 166 genes. Remarkable variation was seen both in locus size (20 - 4950 kb), and gene content, with seven multigenic (≥3 genes) and four monogenic loci. CNV data from control populations was used to further refine the boundaries of these ASD susceptibility loci. Interestingly, our analysis indicates that 15q11.2-13.3, a genomic region prone to chromosomal rearrangements of various sizes, contains three distinct ASD susceptibility CNV loci that vary in their genomic boundaries, CNV types, inheritance patterns, and overlap with CNVs from control populations. In summary, our analysis of AutDB CNV data provides valuable insights into the genomic characteristics of ASD susceptibility CNV loci and could therefore be utilized in various clinical settings and facilitate future genetic research of this disorder.
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Affiliation(s)
- Idan Menashe
- MindSpec, McLean, Virginia, United States of America
- Department of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
- * E-mail: (IM); (SB)
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173
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Diagnostic yield of array comparative genomic hybridization in adults with autism spectrum disorders. Genet Med 2013; 16:70-7. [PMID: 23765050 DOI: 10.1038/gim.2013.78] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 04/18/2013] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Array comparative genomic hybridization is available for the evaluation of autism spectrum disorders. The diagnostic yield of testing is 5-18% in children with developmental disabilities, including autism spectrum disorders and multiple congenital anomalies. The yield of array comparative genomic hybridization in the adult autism spectrum disorder population is unknown. METHODS We performed a retrospective chart review for 40 consecutive patients referred for genetic evaluation of autism from July 2009 through April 2012. Four pediatric patients were excluded. Medical history and prior testing were reviewed. Clinical genetic evaluation and testing were offered to all patients. RESULTS The study population comprised 36 patients (age range 18-45, mean 25.3 years). An autism spectrum disorder diagnosis was confirmed in 34 of 36 patients by medical record review. One patient had had an abnormal karyotype; none had prior array comparative genomic hybridization testing. Of the 23 patients with autism who underwent array comparative genomic hybridization, 2 of 23 (8.7%) had pathogenic or presumed pathogenic abnormalities and 2 of 23 (8.7%) had likely pathogenic copy-number variants. An additional 5 of 23 (22%) of autism patients had variants of uncertain significance without subclassification. CONCLUSION Including one patient newly diagnosed with fragile X syndrome, our data showed abnormal or likely pathogenic findings in 5 of 24 (21%) adult autism patients. Genetic reevaluation in adult autism patients is warranted.
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174
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Betancur C, Buxbaum JD. SHANK3 haploinsufficiency: a "common" but underdiagnosed highly penetrant monogenic cause of autism spectrum disorders. Mol Autism 2013; 4:17. [PMID: 23758743 PMCID: PMC3695795 DOI: 10.1186/2040-2392-4-17] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 05/29/2013] [Indexed: 11/10/2022] Open
Abstract
Autism spectrum disorders (ASD) are etiologically heterogeneous, with hundreds of rare, highly penetrant mutations and genomic imbalances involved, each contributing to a very small fraction of cases. In this issue of Molecular Autism, Soorya and colleagues evaluated 32 patients with Phelan-McDermid syndrome, caused by either deletion of 22q13.33 or SHANK3 mutations, using gold-standard diagnostic assessments and showed that 84% met criteria for ASD, including 75% meeting criteria for autism. This study and prior studies demonstrate that this syndrome appears to be one of the more penetrant causes of ASD. In this companion review, we show that in samples ascertained for ASD, SHANK3 haploinsufficiency is one of the more prevalent monogenic causes of ASD, explaining at least 0.5% of cases. We note that SHANK3 haploinsufficiency remains underdiagnosed in ASD and developmental delay, although with the increasingly widespread use of chromosomal microarray analysis and targeted sequencing of SHANK3, the number of cases is bound to rise.
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175
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Soorya L, Kolevzon A, Zweifach J, Lim T, Dobry Y, Schwartz L, Frank Y, Wang AT, Cai G, Parkhomenko E, Halpern D, Grodberg D, Angarita B, Willner JP, Yang A, Canitano R, Chaplin W, Betancur C, Buxbaum JD. Prospective investigation of autism and genotype-phenotype correlations in 22q13 deletion syndrome and SHANK3 deficiency. Mol Autism 2013; 4:18. [PMID: 23758760 PMCID: PMC3707861 DOI: 10.1186/2040-2392-4-18] [Citation(s) in RCA: 220] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 04/23/2013] [Indexed: 01/30/2023] Open
Abstract
Background 22q13 deletion syndrome, also known as Phelan-McDermid syndrome, is a neurodevelopmental disorder characterized by intellectual disability, hypotonia, delayed or absent speech, and autistic features. SHANK3 has been identified as the critical gene in the neurological and behavioral aspects of this syndrome. The phenotype of SHANK3 deficiency has been described primarily from case studies, with limited evaluation of behavioral and cognitive deficits. The present study used a prospective design and inter-disciplinary clinical evaluations to assess patients with SHANK3 deficiency, with the goal of providing a comprehensive picture of the medical and behavioral profile of the syndrome. Methods A serially ascertained sample of patients with SHANK3 deficiency (n = 32) was evaluated by a team of child psychiatrists, neurologists, clinical geneticists, molecular geneticists and psychologists. Patients were evaluated for autism spectrum disorder using the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule-G. Results Thirty participants with 22q13.3 deletions ranging in size from 101 kb to 8.45 Mb and two participants with de novo SHANK3 mutations were included. The sample was characterized by high rates of autism spectrum disorder: 27 (84%) met criteria for autism spectrum disorder and 24 (75%) for autistic disorder. Most patients (77%) exhibited severe to profound intellectual disability and only five (19%) used some words spontaneously to communicate. Dysmorphic features, hypotonia, gait disturbance, recurring upper respiratory tract infections, gastroesophageal reflux and seizures were also common. Analysis of genotype-phenotype correlations indicated that larger deletions were associated with increased levels of dysmorphic features, medical comorbidities and social communication impairments related to autism. Analyses of individuals with small deletions or point mutations identified features related to SHANK3 haploinsufficiency, including ASD, seizures and abnormal EEG, hypotonia, sleep disturbances, abnormal brain MRI, gastroesophageal reflux, and certain dysmorphic features. Conclusions This study supports findings from previous research on the severity of intellectual, motor, and speech impairments seen in SHANK3 deficiency, and highlights the prominence of autism spectrum disorder in the syndrome. Limitations of existing evaluation tools are discussed, along with the need for natural history studies to inform clinical monitoring and treatment development in SHANK3 deficiency.
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Affiliation(s)
- Latha Soorya
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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176
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Driessnack M, Daack-Hirsch S, Downing N, Hanish A, Shah LL, Alasagheirin M, Simon CM, Williams JK. The disclosure of incidental genomic findings: an "ethically important moment" in pediatric research and practice. J Community Genet 2013; 4:435-44. [PMID: 23572417 DOI: 10.1007/s12687-013-0145-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 03/26/2013] [Indexed: 12/28/2022] Open
Abstract
Although there are numerous position papers on the issues and challenges surrounding disclosure of incidental genomic findings involving children, there is very little research. To fill this gap, the purpose of this study was to explore the perspectives of multiple professional (N = 103) and public (N = 63) stakeholders using both interviews and focus groups. Using qualitative analysis, we identified one overarching theme, "It's hard for us; it's hard for them," and three subthemes/questions: "What to disclose?," "Who gets the information?," and "What happens later?" Perspectives differed between professional (Institutional Review Board chairs, clinicians, and researchers) and public stakeholders. While professionals focused on the complexities of what to disclose, the lay public stated that parents should have all information laid out for them. Professionals pondered multiple parent and child situations, while the public identified parents as informational gatekeepers who know their children best. Professionals described the potential requirement for follow-up over time as a logistical "nightmare," while the public believed that parents have the responsibility for managing their children's health information over time. However, the parent role as gatekeeper was seen as time limited and in need of professional support and backup. Our findings present a case for needed dialogue around what we propose as an "ethically important moment," with the goal of protecting and respecting the viewpoints of all stakeholders when policies regarding children are developed.
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Affiliation(s)
- Martha Driessnack
- Oregon Health & Science University, School of Nursing, 3455 SW US Veterans Hospital Road, Portland, OR, USA,
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177
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Density matters: comparison of array platforms for detection of copy-number variation and copy-neutral abnormalities. Genet Med 2013; 15:706-12. [DOI: 10.1038/gim.2013.36] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/20/2013] [Indexed: 01/20/2023] Open
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178
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Schaefer GB, Mendelsohn NJ. Clinical genetics evaluation in identifying the etiology of autism spectrum disorders: 2013 guideline revisions. Genet Med 2013; 15:399-407. [PMID: 23519317 DOI: 10.1038/gim.2013.32] [Citation(s) in RCA: 321] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The autism spectrum disorders are a collective of conditions that have in common impaired socialization and communication in association with stereotypic behaviors. The reported incidence of autism spectrum disorders has increased dramatically over the past two decades. In addition, increased attention has been paid to these conditions by both lay and professional groups. These trends have resulted in an increase in the number of referrals to clinical geneticist for the evaluation of persons with autism spectrum disorders. The primary roles of the geneticist in this process are to define etiology when possible, to provide genetic counseling, and to contribute to case management. In deciding on the appropriate evaluation for a particular patient, the geneticist will consider a host of factors: (i) ensuring an accurate diagnosis of autism before proceeding with any investigation; (ii) discussing testing options, diagnostic yields, and family investment before proceeding with an evaluation; (iii) communicating and coordinating with the patient-centered medical home (PCMH); (iv) assessing the continuously expanding and evolving list of available laboratory-testing modalities in light of the published literature; (v) recognizing the expanded phenotypes of well-described syndromic and metabolic conditions that overlap with autism spectrum disorders; and (vi) defining an individualized evaluation plan based on the unique history and clinical features of a given patient. The guidelines in this paper have been developed to assist the clinician in the consideration of these factors. It updates the original publication from 2008.Genet Med 2013:15(5):399-407.
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Affiliation(s)
- G Bradley Schaefer
- Department of Genetics and Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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179
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Riggs E, Wain K, Riethmaier D, Smith-Packard B, Faucett W, Hoppman N, Thorland E, Patel V, Miller D. Chromosomal microarray impacts clinical management. Clin Genet 2013; 85:147-53. [DOI: 10.1111/cge.12107] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/18/2013] [Accepted: 01/18/2013] [Indexed: 11/30/2022]
Affiliation(s)
- E.R. Riggs
- Department of Human Genetics; Emory University School of Medicine; Atlanta GA USA
| | - K.E. Wain
- Department of Laboratory Medicine & Pathology; Mayo Clinic; Rochester MN USA
| | | | | | | | - N. Hoppman
- Department of Laboratory Medicine & Pathology; Mayo Clinic; Rochester MN USA
| | - E.C. Thorland
- Department of Laboratory Medicine & Pathology; Mayo Clinic; Rochester MN USA
| | - V.C. Patel
- Department of Human Genetics; Emory University School of Medicine; Atlanta GA USA
| | - D.T. Miller
- Department of Laboratory Medicine; Children's Hospital Boston; Boston MA USA
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180
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Carter MT, Scherer SW. Autism spectrum disorder in the genetics clinic: a review. Clin Genet 2013; 83:399-407. [PMID: 23425232 DOI: 10.1111/cge.12101] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 01/14/2013] [Accepted: 01/14/2013] [Indexed: 01/08/2023]
Abstract
Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental disorders affecting social communication, language and behavior. The underlying cause(s) in a given individual is often elusive, with the exception of clinically recognizable genetic syndromes with readily available molecular diagnosis, such as fragile X syndrome. Clinical geneticists approach patients with ASDs by ruling out known genetic and genomic syndromes, leaving more than 80% of families without a definitive diagnosis and an uncertain risk of recurrence. Advances in microarray technology and next-generation sequencing are revealing rare variants in genes with important roles in synapse formation, function and maintenance. This review will focus on the clinical approach to ASDs, given the current state of knowledge about their complex genetic architecture.
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Affiliation(s)
- M T Carter
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada.
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181
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Abstract
PURPOSE OF REVIEW To provide an updated overview of autism spectrum disorders (ASDs), with particular attention to the pediatrician's role in assessing and managing patients with ASDs. RECENT FINDINGS Clinical perspectives on ASDs continue to evolve. The prevalence of ASDs in the United States continues to rise, and pediatricians are being tasked with the responsibility for universal screening. Further changes in its epidemiology will undoubtedly result from anticipated changes in the diagnostic criteria put forth in the upcoming revision to the Diagnostic and Statistical Manual (5th edition). Although there have been considerable advances in identifying a genetic cause in many more cases, the cause remains elusive in most cases. Recent studies of concordant twins suggest there is a stronger environmental component than previously believed. Research suggests earlier diagnosis may be feasible in some cases, and a new treatment approach has been shown to be effective in very young children. Although there have not been any large-scale advances in the medical treatment, some isolated successes have been reported and other promising therapies are now being investigated. SUMMARY Clinical guidelines for ASDs are evolving, with updated diagnostic criteria expected and revised recommendations for evaluation also imminent. This article provides pediatricians with a clinical overview of ASD - with an emphasis on the clinical considerations relating to screening, evaluation, and management.
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182
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Klein S, Sharifi-Hannauer P, Martinez-Agosto JA. Macrocephaly as a clinical indicator of genetic subtypes in autism. Autism Res 2013; 6:51-6. [PMID: 23361946 DOI: 10.1002/aur.1266] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 10/22/2012] [Indexed: 11/10/2022]
Abstract
An association between autism and macrocephaly has been previously described. A subset of cases with extreme macrocephaly (>3 standard deviation [SD], 99.7th percentile) have been correlated to mutations in the gene phosphatase and tensin homolog (PTEN). However, the phenotypic and genetic characterization of the remaining cases remains unclear. We report the phenotypic classification and genetic testing evaluation of a cohort of 33 patients with autism and macrocephaly. Within our cohort, we confirm the association of PTEN mutations and extreme macrocephaly (>3 SD, 99.7th percentile) and identify mutations in 22% of cases, including three novel PTEN mutations. In addition, we define three phenotypic subgroups: (a) those cases associated with somatic overgrowth, (b) those with disproportionate macrocephaly, and (c) those with relative macrocephaly. We have devised a novel way to segregate patients into these subgroups that will aide in the stratification of autism macrocephaly cases. Within these subgroups, we further expand the genetic etiologies for autism cases with macrocephaly by describing two novel suspected pathogenic copy number variants located at 6q23.2 and 10q24.32. These findings demonstrate the phenotypic heterogeneity of autism cases associated with macrocephaly and their genetic etiologies. The clinical yield from PTEN mutation analysis is 22% and 9% from chromosomal microarray (CMA) testing within this cohort. The identification of three distinct phenotypic subgroups within macrocephaly autism patients may allow for the identification of their respective distinct genetic etiologies that to date have remained elusive.
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Affiliation(s)
- Steven Klein
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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183
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Identification of rare recurrent copy number variants in high-risk autism families and their prevalence in a large ASD population. PLoS One 2013; 8:e52239. [PMID: 23341896 PMCID: PMC3544904 DOI: 10.1371/journal.pone.0052239] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 11/09/2012] [Indexed: 11/29/2022] Open
Abstract
Structural variation is thought to play a major etiological role in the development of autism spectrum disorders (ASDs), and numerous studies documenting the relevance of copy number variants (CNVs) in ASD have been published since 2006. To determine if large ASD families harbor high-impact CNVs that may have broader impact in the general ASD population, we used the Affymetrix genome-wide human SNP array 6.0 to identify 153 putative autism-specific CNVs present in 55 individuals with ASD from 9 multiplex ASD pedigrees. To evaluate the actual prevalence of these CNVs as well as 185 CNVs reportedly associated with ASD from published studies many of which are insufficiently powered, we designed a custom Illumina array and used it to interrogate these CNVs in 3,000 ASD cases and 6,000 controls. Additional single nucleotide variants (SNVs) on the array identified 25 CNVs that we did not detect in our family studies at the standard SNP array resolution. After molecular validation, our results demonstrated that 15 CNVs identified in high-risk ASD families also were found in two or more ASD cases with odds ratios greater than 2.0, strengthening their support as ASD risk variants. In addition, of the 25 CNVs identified using SNV probes on our custom array, 9 also had odds ratios greater than 2.0, suggesting that these CNVs also are ASD risk variants. Eighteen of the validated CNVs have not been reported previously in individuals with ASD and three have only been observed once. Finally, we confirmed the association of 31 of 185 published ASD-associated CNVs in our dataset with odds ratios greater than 2.0, suggesting they may be of clinical relevance in the evaluation of children with ASDs. Taken together, these data provide strong support for the existence and application of high-impact CNVs in the clinical genetic evaluation of children with ASD.
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184
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Beaudet AL. The utility of chromosomal microarray analysis in developmental and behavioral pediatrics. Child Dev 2013; 84:121-32. [PMID: 23311723 DOI: 10.1111/cdev.12050] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chromosomal microarray analysis (CMA) has emerged as a powerful new tool to identify genomic abnormalities associated with a wide range of developmental disabilities including congenital malformations, cognitive impairment, and behavioral abnormalities. CMA includes array comparative genomic hybridization (CGH) and single nucleotide polymorphism (SNP) arrays, both of which are useful for detection of genomic copy number variants (CNV) such as microdeletions and microduplications. The frequency of disease-causing CNVs is highest (20%-25%) in children with moderate to severe intellectual disability accompanied by malformations or dysmorphic features. Disease-causing CNVs are found in 5%-10% of cases of autism, being more frequent in severe phenotypes. CMA has replaced Giemsa-banded karyotype as the first-tier test for genetic evaluation of children with developmental and behavioral disabilities.
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185
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Autism genetic testing: a qualitative study of awareness, attitudes, and experiences among parents of children with autism spectrum disorders. Genet Med 2013; 15:274-81. [DOI: 10.1038/gim.2012.145] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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186
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Abstract
Recent advances in genetic testing technology have made chromosome microarray analysis (CMA) a first-tier clinical diagnostic test for Autism Spectrum Disorders (ASDs). Two main types of microarrays are available, single nucleotide polymorphism (SNP) arrays and array comparative genomic hybridization (aCGH), each with its own advantages and disadvantages in ASDs testing. Rare genetic variants, and copy number variants (CNVs) in particular, have been shown to play a major role in ASDs. More than 200 autism susceptibility genes have been identified to date, and complex patterns of inheritance, such as oligogenic heterozygosity, appear to contribute to the etiopathogenesis of ASDs. Incomplete penetrance and variable expressivity represent particular challenges in the interpretation of CMA testing of autistic individuals. This review aims to provide an overview of autism genetics for the practicing physician and gives hands-on advice on how to follow-up on abnormal CMA findings in individuals with neuropsychiatric disorders.
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Affiliation(s)
- Karsten M Heil
- Faculty of Medicine, University of Heidelberg, Im Neuenheimer Feld 134b, 69120 Heidelberg, Germany.
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187
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Isaksen J, Bryn V, Diseth TH, Heiberg A, Schjølberg S, Skjeldal OH. Children with autism spectrum disorders - the importance of medical investigations. Eur J Paediatr Neurol 2013; 17:68-76. [PMID: 22954514 DOI: 10.1016/j.ejpn.2012.08.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 06/29/2012] [Accepted: 08/11/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND Considerable knowledge about medical comorbidity in cases of Autism Spectrum Disorders (ASD) is available, still it is not well established how extensive the medical investigations should be in individual cases. The aim is to explore proportions of possible specific medical conditions in ASD. METHODS 79 subjects went through extensive medical evaluations according to pre-defined procedures, including medical and developmental history, physical and biomedical investigations. RESULTS Clinical neurological findings were quite common, and we found a high number of pathological findings in the additional medical investigations. Our study revealed that these pathological deviations occurred more frequently in patients with childhood autism than in the other diagnostic sub-groups, the exception were chromosomal findings which occurred more often in patients not-diagnosed with childhood autism. CONCLUSION Medical and laboratory investigations should still be performed as a consequence of the patient's history, clinical presentations or family history. We should basically continue the use of non-routine and invasive procedures which do not put the patient at some unnecessary risk, in the absence of relevant clinical indications.
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Affiliation(s)
- Jørn Isaksen
- Department of Habilitation, Innlandet Hospital Trust, Maihaugveien 4, 2609 Lillehammer, Norway.
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188
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Eriksson MA, Westerlund J, Hedvall Å, Åmark P, Gillberg C, Fernell E. Medical conditions affect the outcome of early intervention in preschool children with autism spectrum disorders. Eur Child Adolesc Psychiatry 2013; 22:23-33. [PMID: 22836733 DOI: 10.1007/s00787-012-0312-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 07/14/2012] [Indexed: 11/28/2022]
Abstract
The aim was to explore the frequency of genetic and other medical conditions, including epilepsy, in a population-based group of 208 preschool children with early diagnosis of Autism spectrum disorders (ASD) and to relate outcome at a 2-year follow-up to the co-existing medical findings. They had all received early intervention. The Vineland Adaptive Behaviour Scales (VABS-II) composite score served as the primary outcome measure. In the total group, 38/208 children (18 %) had a significant medical or genetic condition. Epilepsy was present in 6.3 % at the first assessment and in 8.6 % at follow-up and was associated with more severe intellectual impairment. A history of regression was reported in 22 %. Children with any medical/genetic condition, including epilepsy, as well as children with a history of regression had significantly lower VABS-II scores at the 2-year follow-up. Children with a medical/genetic condition, including epilepsy, had been diagnosed with ASD at an earlier age than those without such conditions, and early age at diagnosis also correlated negatively with adaptive functioning outcome. The results underscore the importance of considering medical/genetic aspects in all young children with ASD and the requirement to individualize and tailor interventions according to their specific needs.
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Affiliation(s)
- Mats Anders Eriksson
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
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189
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Abstract
Purpose: Although an increasing number of copy-number variations are being identified as susceptibility loci for a variety of pediatric diseases, the penetrance of these copy-number variations remains mostly unknown. This poses challenges for counseling, both for recurrence risks and prenatal diagnosis. We sought to provide empiric estimates for penetrance for some of these recurrent, disease-susceptibility loci. Methods: We conducted a Bayesian analysis, based on the copy-number variation frequencies in control populations (n = 22,246) and in our database of >48,000 postnatal microarray-based comparative genomic hybridization samples. The background risk for congenital anomalies/developmental delay/intellectual disability was assumed to be ~5%. Copy-number variations studied were 1q21.1 proximal duplications, 1q21.1 distal deletions and duplications, 15q11.2 deletions, 16p13.11 deletions, 16p12.1 deletions, 16p11.2 proximal and distal deletions and duplications, 17q12 deletions and duplications, and 22q11.21 duplications. Results: Estimates for the risk of an abnormal phenotype ranged from 10.4% for 15q11.2 deletions to 62.4% for distal 16p11.2 deletions. Conclusion: This model can be used to provide more precise estimates for the chance of an abnormal phenotype for many copy-number variations encountered in the prenatal setting. By providing the penetrance, additional, critical information can be given to prospective parents in the genetic counseling session.
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190
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Characteristics and predictive value of blood transcriptome signature in males with autism spectrum disorders. PLoS One 2012; 7:e49475. [PMID: 23227143 PMCID: PMC3515554 DOI: 10.1371/journal.pone.0049475] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 10/09/2012] [Indexed: 01/22/2023] Open
Abstract
Autism Spectrum Disorders (ASD) is a spectrum of highly heritable neurodevelopmental disorders in which known mutations contribute to disease risk in 20% of cases. Here, we report the results of the largest blood transcriptome study to date that aims to identify differences in 170 ASD cases and 115 age/sex-matched controls and to evaluate the utility of gene expression profiling as a tool to aid in the diagnosis of ASD. The differentially expressed genes were enriched for the neurotrophin signaling, long-term potentiation/depression, and notch signaling pathways. We developed a 55-gene prediction model, using a cross-validation strategy, on a sample cohort of 66 male ASD cases and 33 age-matched male controls (P1). Subsequently, 104 ASD cases and 82 controls were recruited and used as a validation set (P2). This 55-gene expression signature achieved 68% classification accuracy with the validation cohort (area under the receiver operating characteristic curve (AUC): 0.70 [95% confidence interval [CI]: 0.62–0.77]). Not surprisingly, our prediction model that was built and trained with male samples performed well for males (AUC 0.73, 95% CI 0.65–0.82), but not for female samples (AUC 0.51, 95% CI 0.36–0.67). The 55-gene signature also performed robustly when the prediction model was trained with P2 male samples to classify P1 samples (AUC 0.69, 95% CI 0.58–0.80). Our result suggests that the use of blood expression profiling for ASD detection may be feasible. Further study is required to determine the age at which such a test should be deployed, and what genetic characteristics of ASD can be identified.
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191
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Zarate YA, Dwivedi A, Bartel FO, Bellomo MA, Cathey SS, Champaigne NL, Clarkson LK, Dupont BR, Everman DB, Geer JS, Gordon BC, Lichty AW, Lyons MJ, Rogers RC, Saul RA, Schroer RJ, Skinner SA, Stevenson RE. Clinical utility of the X-chromosome array. Am J Med Genet A 2012. [PMID: 23208842 DOI: 10.1002/ajmg.a.35698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Previous studies have limited the use of specific X-chromosome array designed platforms to the evaluation of patients with intellectual disability. In this retrospective analysis, we reviewed the clinical utility of an X-chromosome array in a variety of scenarios. We divided patients according to the indication for the test into four defined categories: (1) autism spectrum disorders and/or developmental delay and/or intellectual disability (ASDs/DD/ID) with known family history of neurocognitive disorders; (2) ASDs/DD/ID without known family history of neurocognitive disorders; (3) breakpoint definition of an abnormality detected by a different cytogenetic test; and (4) evaluation of suspected or known X-linked conditions. A total of 59 studies were ordered with 27 copy number variants detected in 25 patients (25/59 = 42%). The findings were deemed pathogenic/likely pathogenic (16/59 = 27%), benign (4/59 = 7%) or uncertain (7/59 = 12%). We place particular emphasis on the utility of this test for the diagnostic evaluation of families affected with X-linked conditions and how it compares to whole genome arrays in this setting. In conclusion, the X-chromosome array frequently detects genomic alterations of the X chromosome and it has advantages when evaluating some specific X-linked conditions. However, careful interpretation and correlation with clinical findings is needed to determine the significance of such changes. When the X-chromosome array was used to confirm a suspected X-linked condition, it had a yield of 63% (12/19) and was useful in the evaluation and risk assessment of patients and families.
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192
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Desale M, Worden LT, Cohen JS, Wilms Floet AM, Hoon AH. Diagnostic evaluation in children with developmental delay: a cautionary tale for genetic testing. Clin Pediatr (Phila) 2012; 51:1208-10. [PMID: 23034944 DOI: 10.1177/0009922812460916] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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193
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A discovery resource of rare copy number variations in individuals with autism spectrum disorder. G3-GENES GENOMES GENETICS 2012; 2:1665-85. [PMID: 23275889 PMCID: PMC3516488 DOI: 10.1534/g3.112.004689] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 10/24/2012] [Indexed: 12/15/2022]
Abstract
The identification of rare inherited and de novo copy number variations (CNVs) in human subjects has proven a productive approach to highlight risk genes for autism spectrum disorder (ASD). A variety of microarrays are available to detect CNVs, including single-nucleotide polymorphism (SNP) arrays and comparative genomic hybridization (CGH) arrays. Here, we examine a cohort of 696 unrelated ASD cases using a high-resolution one-million feature CGH microarray, the majority of which were previously genotyped with SNP arrays. Our objective was to discover new CNVs in ASD cases that were not detected by SNP microarray analysis and to delineate novel ASD risk loci via combined analysis of CGH and SNP array data sets on the ASD cohort and CGH data on an additional 1000 control samples. Of the 615 ASD cases analyzed on both SNP and CGH arrays, we found that 13,572 of 21,346 (64%) of the CNVs were exclusively detected by the CGH array. Several of the CGH-specific CNVs are rare in population frequency and impact previously reported ASD genes (e.g., NRXN1, GRM8, DPYD), as well as novel ASD candidate genes (e.g., CIB2, DAPP1, SAE1), and all were inherited except for a de novo CNV in the GPHN gene. A functional enrichment test of gene-sets in ASD cases over controls revealed nucleotide metabolism as a potential novel pathway involved in ASD, which includes several candidate genes for follow-up (e.g., DPYD, UPB1, UPP1, TYMP). Finally, this extensively phenotyped and genotyped ASD clinical cohort serves as an invaluable resource for the next step of genome sequencing for complete genetic variation detection.
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194
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Canitano R. Novel treatments in autism spectrum disorders: from synaptic dysfunction to experimental therapeutics. Behav Brain Res 2012. [PMID: 23202136 DOI: 10.1016/j.bbr.2012.11.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent discoveries and advances in genetics and neuroscience have provided deeper understanding of the complex neurobiology of ASD. The development of novel treatments is strictly dependent on these findings in order to design new strategies in the pharmacotherapy of ASD. At this time, therapeutics are limited to treating associated core, symptoms. Studies of single gene disorders, such as Phelan-McDermid syndrome, Fragile X and Tuberous Sclerosis, might be of significant help since the neurobiology of these disorders is clearer and clinical trials are already underway for these conditions. The pathogenesis paradigm shift of ASD towards synaptic abnormalities has led to current research of the pathways to disease, which involves multiple dynamic systems. Interest in oxytocin is growing as it has been recognized to be implicated in social development and affiliative behaviours. In the future, progress is expected in possible new options for therapeutics in ASD. Children and adolescents with ASD and their families can provide vital information about their experiences with new treatments, which should be a priority for future research.
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Affiliation(s)
- Roberto Canitano
- Division of Child Neuropsychiatry, University Hospital of Siena, Italy.
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195
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Ellison JW, Ravnan JB, Rosenfeld JA, Morton SA, Neill NJ, Williams MS, Lewis J, Torchia BS, Walker C, Traylor RN, Moles K, Miller E, Lantz J, Valentin C, Minier SL, Leiser K, Powell BR, Wilks TM, Shaffer LG. Clinical utility of chromosomal microarray analysis. Pediatrics 2012; 130:e1085-95. [PMID: 23071206 DOI: 10.1542/peds.2012-0568] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To test the hypothesis that chromosomal microarray analysis frequently diagnoses conditions that require specific medical follow-up and that referring physicians respond appropriately to abnormal test results. METHODS A total of 46,298 postnatal patients were tested by chromosomal microarray analysis for a variety of indications, most commonly intellectual disability/developmental delay, congenital anomalies, dysmorphic features, and neurobehavioral problems. The frequency of detection of abnormalities associated with actionable clinical features was tallied, and the rate of physician response to a subset of abnormal tests results was monitored. RESULTS A total of 2088 diagnoses were made of more than 100 different disorders that have specific clinical features that warrant follow-up. The detection rate for these conditions using high-resolution whole-genome microarrays was 5.4%, which translates to 35% of all clinically significant abnormal test results identified in our laboratory. In a subset of cases monitored for physician response, appropriate clinical action was taken more than 90% of the time as a direct result of the microarray finding. CONCLUSIONS The disorders diagnosed by chromosomal microarray analysis frequently have clinical features that need medical attention, and physicians respond to the diagnoses with specific clinical actions, thus arguing that microarray testing provides clinical utility for a significant number of patients tested.
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Affiliation(s)
- Jay W Ellison
- Signature Genomic Laboratories, PerkinElmer, Inc, Spokane, Washington 99207, USA.
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196
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Perrin JM, Coury DL, Jones N, Lajonchere C. The Autism Treatment Network and Autism Intervention Research Network on Physical Health: future directions. Pediatrics 2012; 130 Suppl 2:S198-201. [PMID: 23118252 DOI: 10.1542/peds.2012-0900s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- James M Perrin
- Department of Pediatrics, Harvard Medical School, MassGeneral Hospital for Children, 100 Cambridge St, #1542, Boston, MA 02114, USA.
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197
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Coughlin CR, Scharer GH, Shaikh TH. Clinical impact of copy number variation analysis using high-resolution microarray technologies: advantages, limitations and concerns. Genome Med 2012; 4:80. [PMID: 23114084 PMCID: PMC3580449 DOI: 10.1186/gm381] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Copy number variation (CNV) analysis has had a major impact on the field of medical genetics, providing a mechanism to identify disease-causing genomic alterations in an unprecedented number of diseases and phenotypes. CNV analysis is now routinely used in the clinical diagnostic laboratory, and has led to a significant increase in the detection of chromosomal abnormalities. These findings are used for prenatal decision making, clinical management and genetic counseling. Although a powerful tool to identify genomic alterations, CNV analysis may also result in the detection of genomic alterations that have unknown clinical significance or reveal unintended information. This highlights the importance of informed consent and genetic counseling for clinical CNV analysis. This review examines the advantages and limitations of CNV discovery in the clinical diagnostic laboratory, as well as the impact on the clinician and family.
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Affiliation(s)
- Curtis R Coughlin
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Denver, Aurora, CO 80045, USA
| | - Gunter H Scharer
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Denver, Aurora, CO 80045, USA ; Intellectual and Developmental Disabilities Research Center, University of Colorado Denver, Aurora, CO 80045, USA
| | - Tamim H Shaikh
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Denver, Aurora, CO 80045, USA ; Intellectual and Developmental Disabilities Research Center, University of Colorado Denver, Aurora, CO 80045, USA
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198
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KANG JIUN, KOO SUNHOE. Clinical implementation of chromosomal microarray technology in prenatal diagnosis (Review). Mol Med Rep 2012; 6:1219-22. [DOI: 10.3892/mmr.2012.1116] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 09/17/2012] [Indexed: 11/06/2022] Open
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199
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Abstract
This editorial discusses the importance of autism research, noting areas of progress and ongoing challenges and focusing on studies of the etiology, pathophysiology, and treatment of autism spectrum disorders.
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200
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Sahin M. Targeted treatment trials for tuberous sclerosis and autism: no longer a dream. Curr Opin Neurobiol 2012; 22:895-901. [PMID: 22560338 PMCID: PMC3715752 DOI: 10.1016/j.conb.2012.04.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 04/07/2012] [Indexed: 10/28/2022]
Abstract
Genetic disorders that present with a high incidence of autism spectrum disorders (ASD) offer tremendous potential both for elucidating the underlying neurobiology of ASD and identifying therapeutic drugs and/or drug targets. As a result, clinical trials for genetic disorders associated with ASD are no longer a hope for the future but rather an exciting reality whose time has come. Tuberous sclerosis complex (TSC) is one such genetic disorder that presents with ASD, epilepsy, and intellectual disability. Cell culture and mouse model experiments have identified the mTOR pathway as a therapeutic target in this disease. This review summarizes the advantages of using TSC as model of ASD and the recent advances in the translational and clinical treatment trials in TSC.
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Affiliation(s)
- Mustafa Sahin
- The FM Kirby Neurobiology Center, Department of Neurology, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.
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