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Gholamalizadeh H, Amiri-Shahri M, Rasouli F, Ansari A, Baradaran Rahimi V, Reza Askari V. DNA Methylation in Autism Spectrum Disorders: Biomarker or Pharmacological Target? Brain Sci 2024; 14:737. [PMID: 39199432 PMCID: PMC11352561 DOI: 10.3390/brainsci14080737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/20/2024] [Accepted: 07/21/2024] [Indexed: 09/01/2024] Open
Abstract
Autism spectrum disorder (ASD) is a group of heterogeneous neurodevelopmental disabilities with persistent impairments in cognition, communication, and social behavior. Although environmental factors play a role in ASD etiopathogenesis, a growing body of evidence indicates that ASD is highly inherited. In the last two decades, the dramatic rise in the prevalence of ASD has interested researchers to explore the etiologic role of epigenetic marking and incredibly abnormal DNA methylation. This review aimed to explain the current understanding of the association between changes in DNA methylation signatures and ASD in patients or animal models. We reviewed studies reporting alterations in DNA methylation at specific genes as well as epigenome-wide association studies (EWASs). Finally, we hypothesized that specific changes in DNA methylation patterns could be considered a potential biomarker for ASD diagnosis and prognosis and even a target for pharmacological intervention.
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Affiliation(s)
- Hanieh Gholamalizadeh
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad 13131-99137, Iran;
- Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad 91779-48564, Iran
| | - Maedeh Amiri-Shahri
- Student Research Committee, North Khorasan University of Medical Sciences, Bojnurd 94149-75516, Iran; (M.A.-S.); (F.R.); (A.A.)
- Faculty of Medicine, North Khorasan University of Medical Sciences, Bojnurd 94149-75516, Iran
| | - Fatemeh Rasouli
- Student Research Committee, North Khorasan University of Medical Sciences, Bojnurd 94149-75516, Iran; (M.A.-S.); (F.R.); (A.A.)
- Faculty of Medicine, North Khorasan University of Medical Sciences, Bojnurd 94149-75516, Iran
| | - Arina Ansari
- Student Research Committee, North Khorasan University of Medical Sciences, Bojnurd 94149-75516, Iran; (M.A.-S.); (F.R.); (A.A.)
- Faculty of Medicine, North Khorasan University of Medical Sciences, Bojnurd 94149-75516, Iran
| | - Vafa Baradaran Rahimi
- Department of Cardiovascular Diseases, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad 91779-48564, Iran;
| | - Vahid Reza Askari
- Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad 91779-48564, Iran
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Chien WH, Chen CH, Cheng MC, Wu YY, Gau SSF. Neuregulin 2 Is a Candidate Gene for Autism Spectrum Disorder. Int J Mol Sci 2024; 25:5547. [PMID: 38791584 PMCID: PMC11121989 DOI: 10.3390/ijms25105547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/04/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024] Open
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with heterogeneous and complex genetic underpinnings. Our previous microarray gene expression profiling identified significantly different neuregulin-2 gene (NRG2) expression between ASD patients and controls. Thus, we aimed to clarify whether NRG2 is a candidate gene associated with ASD. The study consisted of two stages. First, we used real-time quantitative PCR in 20 ASDs and 20 controls to confirm the microarray gene expression profiling results. The average NRG2 gene expression level in patients with ASD (3.23 ± 2.80) was significantly lower than that in the controls (9.27 ± 4.78, p < 0.001). Next, we conducted resequencing of all the exons of NRG2 in a sample of 349 individuals with ASD, aiming to identify variants of the NRG2 associated with ASD. We identified three variants, including two single nucleotide variants (SNVs), IVS3 + 13A > G (rs889022) and IVS10 + 32T > A (rs182642591), and one small deletion at exon 11 of NRG2 (delGCCCGG, rs933769137). Using data from the Taiwan Biobank as the controls, we found no significant differences in allele frequencies of rs889022 and rs182642591 between two groups. However, there is a significant difference in the genotype and allele frequency distribution of rs933769137 between ASDs and controls (p < 0.0001). The small deletion is located in the EGF-like domain at the C-terminal of the NRG2 precursor protein. Our findings suggest that NRG2 might be a susceptibility gene for ASD.
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Affiliation(s)
- Wei-Hsien Chien
- Department of Occupational Therapy, College of Medicine, Fu Jen Catholic University, New Taipei City 242062, Taiwan
| | - Chia-Hsiang Chen
- Department of Psychiatry, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (C.-H.C.); (Y.-Y.W.)
| | - Min-Chih Cheng
- Department of Psychiatry, Yuli Branch, Taipei Veterans General Hospital, Hualien 981, Taiwan;
| | - Yu-Yu Wu
- Department of Psychiatry, Linkou Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (C.-H.C.); (Y.-Y.W.)
| | - Susan Shur-Fen Gau
- Department of Psychiatry, National Taiwan University Hospital, Taipei 10002, Taiwan
- Graduate Institute of Brain and Mind Sciences and Graduate of Clinical Medicine, National Taiwan University, Taipei 10002, Taiwan
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Sun L, Wang X, Wang X, Cui X, Li G, Wang L, Wang L, Song M, Yu L. Genome-wide DNA methylation profiles of autism spectrum disorder. Psychiatr Genet 2022; 32:131-145. [PMID: 35353793 DOI: 10.1097/ypg.0000000000000314] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVES We aimed to identify differentially methylated genes and related signaling pathways in autism spectrum disorder (ASD). METHODS First, the DNA methylation profile in the brain samples (GSE131706 and GSE80017) and peripheral blood samples (GSE109905) was downloaded from the Gene Expression Omnibus database (GEO) dataset, followed by identification of differentially methylated genes and functional analysis. Second, the GSE109905 data set was used to further validate the methylation state and test the ability to diagnose disease of identified differentially methylated genes. Third, expression measurement of selected differentially methylated genes was performed in whole blood from an independent sample. Finally, protein-protein interaction (PPI) network of core differentially methylated genes was constructed. RESULTS Totally, 74 differentially methylated genes were identified in ASD, including 38 hypermethylated genes and 36 hypomethylated genes. 15 differentially methylated genes were further identified after validation in the GSE109905 data set. Among these, major histocompatibility complex (HLA)-DQA1 was involved in the molecular function of myosin heavy chain class II receptor activity; HLA-DRB5 was involved in the signaling pathways of cell adhesion molecules, Epstein-Barr virus infection and antigen processing and presentation. In the PPI analysis, the interaction pairs of HLA-DQA1 and HLA-DRB5, FMN2 and ACTR3, and CALCOCO2 and BAZ2B were identified. Interestingly, FMN2, BAZ2B, HLA-DRB5, CALCOCO2 and DUSP22 had a potential diagnostic value for patients with ASD. The expression result of four differentially methylated genes (HLA-DRB5, NTM, IL16 and COL5A3) in the independent sample was consistent with the integrated analysis. CONCLUSIONS Identified differentially methylated genes and enriched signaling pathway could be associated with ASD.
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Affiliation(s)
- Ling Sun
- Mental Health Center, The First Hospital of Hebei Medical University
- Medical Department
| | - Xueyi Wang
- Mental Health Center, The First Hospital of Hebei Medical University
| | - Xia Wang
- Child Health Department (Psychological Behavior Department)
| | | | | | - Le Wang
- Institute of Pediatric Research, Children's Hospital of Hebei Province, China
| | - Lan Wang
- Mental Health Center, The First Hospital of Hebei Medical University
| | - Mei Song
- Mental Health Center, The First Hospital of Hebei Medical University
| | - Lulu Yu
- Mental Health Center, The First Hospital of Hebei Medical University
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Hu Z, Ying X, Huang L, Zhao Y, Zhou D, Liu J, Zhong J, Huang T, Zhang W, Cheng F, Duan S. Association of human serotonin receptor 4 promoter methylation with autism spectrum disorder. Medicine (Baltimore) 2020; 99:e18838. [PMID: 31977880 PMCID: PMC7004686 DOI: 10.1097/md.0000000000018838] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Human serotonin receptor 4 (HTR4) encodes a 5-HT4 receptor involved in learning, memory, depression, anxiety, and feeding behavior. The aim of this study was to investigate the association between the deoxyribonucleic acid (DNA) methylation of HTR4 promoter and autism spectrum disorder (ASD), a disease characterized by communication disorder and repetitive or restrictive behavior.Peripheral blood DNA was obtained from 61 ASD children and 66 healthy children, and the DNA methylation of HTR4 promoter was assessed by quantitative methylation-specific polymerase chain reaction. We used percentage of methylated reference (PMR) to represent DNA methylation level.Due to significant age differences between ASD cases and controls (3 [2, 5] years and 6 [5, 6] years, P = 3.34E-10), we used binary logistic regression analysis for adjustment. Our results showed that the DNA methylation levels of HTR4 promoter were significantly lower in children with ASD than in healthy children (median PMR: 66.23% vs 94.31%,P = .028, age-adjusted P = .034). In addition, the DNA methylation of HTR4 promoter was inversely associated with age in male ASD cases (total cases: r = -0.283, P = .027; male cases: r = -0.431, P = .002; female cases: r = -0.108, P = .752). Dual-luciferase reporter gene assay showed that the reporter gene expression in the strain with recombinant pGL3-promoter-HTR4 plasmid was significantly higher than that in the strain with pGL3-promoter plasmid (fold change = 2.01, P = .0065), indicating that the HTR4 promoter fragment may contain transcription factors to upregulate promoter activity.Our study suggested that hypomethylation of the HTR4 promoter is a potential biomarker for predicting the risk of male ASD.
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Affiliation(s)
- Zhenyu Hu
- Ningbo Kangning Hospital, Ningbo Key Laboratory of Behavioral Neuroscience
| | - Xiuru Ying
- Medical Genetics Center, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Ling Huang
- Ningbo Kangning Hospital, Ningbo Key Laboratory of Behavioral Neuroscience
| | - Yuanzhi Zhao
- Ningbo Kangning Hospital, Ningbo Key Laboratory of Behavioral Neuroscience
| | - Dongsheng Zhou
- Ningbo Kangning Hospital, Ningbo Key Laboratory of Behavioral Neuroscience
| | - Jing Liu
- Medical Genetics Center, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Jie Zhong
- Medical Genetics Center, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Tianyi Huang
- Medical Genetics Center, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Wenwu Zhang
- Ningbo Kangning Hospital, Ningbo Key Laboratory of Behavioral Neuroscience
| | - Fang Cheng
- Ningbo Kangning Hospital, Ningbo Key Laboratory of Behavioral Neuroscience
| | - Shiwei Duan
- Medical Genetics Center, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
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Common variants on 17q25 and gene-gene interactions conferring risk of schizophrenia in Han Chinese population and regulating gene expressions in human brain. Mol Psychiatry 2016; 21:1244-50. [PMID: 26728569 DOI: 10.1038/mp.2015.204] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 10/11/2015] [Accepted: 11/05/2015] [Indexed: 11/09/2022]
Abstract
Recently, two genome-wide association studies (GWASs) of schizophrenia (SCZ) in Han Chinese identified several susceptibility loci. Replication efforts aiming to validate the GWAS findings were made and focused on the top hits. We conducted a more extensive follow-up study in an independent sample of 1471 cases and 1528 matched controls to verify 26 genetic variants by including nine top single-nucleotide polymorphisms (SNPs) that reached genome-wide significance and 17 promising SNPs nominated in the initial discovery phase. rs8073471 in an intron of tubulin-folding cofactor D (TBCD) obtained nominal significance (P<0.01) in single SNP analysis. Logistic regression identified significant interaction between rs3744165 (5'-untranslated region variant of exon 2 of zinc finger protein 750 (ZNF750), and in an intron of TBCD) and rs8073471 (Deviance test P-value=2.77 × 10(-34)). Both SNPs are located at 17q25, an interesting region that has been implicated in SCZ. By using the Genotype-Tissue Expression (GTEx) data set, we implemented an expression quantitative trait loci epistasis analysis to explore the association between the genotype combinations of the two SNPs and gene expression levels in 13 areas of human central nervous system. We observed that rs3744165 × rs8073471 interaction modulated the expression profile of TEAD3 (P=1.87 × 10(-8)), SH3TC2 (P=2.00 × 10(-8)), KCNK9 (P=5.20 × 10(-7)) and PPDPF (P=1.13 × 10(-6)) in postmortem cortex tissue; EFNA1 (P=7.26 × 10(-9)), RNU4ATAC (P=2.32 × 10(-8)) and NUPL2 (P=6.79 × 10(-8)) in cerebellum tissue. To the best of our knowledge, our study is the first one that links TBCD and ZNF750 mutations to SCZ susceptibility and to the transcript levels in human brain tissues. Further efforts are needed to understand the role of those variants in the pathogenesis of SCZ.
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Barua S, Chadman KK, Kuizon S, Buenaventura D, Stapley NW, Ruocco F, Begum U, Guariglia SR, Brown WT, Junaid MA. Increasing maternal or post-weaning folic acid alters gene expression and moderately changes behavior in the offspring. PLoS One 2014; 9:e101674. [PMID: 25006883 PMCID: PMC4090150 DOI: 10.1371/journal.pone.0101674] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 06/10/2014] [Indexed: 01/17/2023] Open
Abstract
Background Studies have indicated that altered maternal micronutrients and vitamins influence the development of newborns and altered nutrient exposure throughout the lifetime may have potential health effects and increased susceptibility to chronic diseases. In recent years, folic acid (FA) exposure has significantly increased as a result of mandatory FA fortification and supplementation during pregnancy. Since FA modulates DNA methylation and affects gene expression, we investigated whether the amount of FA ingested during gestation alters gene expression in the newborn cerebral hemisphere, and if the increased exposure to FA during gestation and throughout the lifetime alters behavior in C57BL/6J mice. Methods Dams were fed FA either at 0.4 mg or 4 mg/kg diet throughout the pregnancy and the resulting pups were maintained on the diet throughout experimentation. Newborn pups brain cerebral hemispheres were used for microarray analysis. To confirm alteration of several genes, quantitative RT-PCR (qRT-PCR) and Western blot analyses were performed. In addition, various behavior assessments were conducted on neonatal and adult offspring. Results Results from microarray analysis suggest that the higher dose of FA supplementation during gestation alters the expression of a number of genes in the newborns’ cerebral hemispheres, including many involved in development. QRT-PCR confirmed alterations of nine genes including down-regulation of Cpn2, Htr4, Zfp353, Vgll2 and up-regulation of Xist, Nkx6-3, Leprel1, Nfix, Slc17a7. The alterations in the expression of Slc17a7 and Vgll2 were confirmed at the protein level. Pups exposed to the higher dose of FA exhibited increased ultrasonic vocalizations, greater anxiety-like behavior and hyperactivity. These findings suggest that although FA plays a significant role in mammalian cellular machinery, there may be a loss of benefit from higher amounts of FA. Unregulated high FA supplementation during pregnancy and throughout the life course may have lasting effects, with alterations in brain development resulting in changes in behavior.
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Affiliation(s)
- Subit Barua
- Department of Developmental Biochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Kathryn K. Chadman
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Salomon Kuizon
- Department of Developmental Biochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Diego Buenaventura
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Nathan W. Stapley
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Felicia Ruocco
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Umme Begum
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Sara R. Guariglia
- Department of Environmental Health Sciences, Columbia University, New York, United States of America
| | - W. Ted Brown
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Mohammed A. Junaid
- Department of Developmental Biochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
- Graduate Center and College of Staten Island, City University of New York, Staten Island, New York, United States of America
- * E-mail:
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Wang P, Carrion P, Qiao Y, Tyson C, Hrynchak M, Calli K, Lopez-Rangel E, Andrieux J, Delobel B, Duban-Bedu B, Thuresson AC, Annerén G, Liu X, Rajcan-Separovic E, Suzanne Lewis ME. Genotype-phenotype analysis of 18q12.1-q12.2 copy number variation in autism. Eur J Med Genet 2013; 56:420-5. [PMID: 23727450 DOI: 10.1016/j.ejmg.2013.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/14/2013] [Indexed: 01/18/2023]
Abstract
Autism Spectrum Disorders (ASD) are complex neurodevelopmental conditions characterized by delays in social interactions and communication as well as displays of restrictive/repetitive interests. DNA copy number variants have been identified as a genomic susceptibility factor in ASDs and imply significant genetic heterogeneity. We report a 7-year-old female with ADOS-G and ADI-R confirmed autistic disorder harbouring a de novo 4 Mb duplication (18q12.1). Our subject displays severely deficient expressive language, stereotypic and repetitive behaviours, mild intellectual disability (ID), focal epilepsy, short stature and absence of significant dysmorphic features. Search of the PubMed literature and DECIPHER database identified 4 additional cases involving 18q12.1 associated with autism and/or ID that overlap our case: one duplication, two deletions and one balanced translocation. Notably, autism and ID are seen with genomic gain or loss at 18q12.1, plus epilepsy and short stature in duplication cases, and hypotonia and tall stature in deletion cases. No consistent dysmorphic features were noted amongst the reviewed cases. We review prospective ASD/ID candidate genes integral to 18q12.1, including those coding for the desmocollin/desmoglein cluster, ring finger proteins 125 and 138, trafficking protein particle complex 8 and dystrobrevin-alpha. The collective clinical and molecular features common to microduplication 18q12.1 suggest that dosage-sensitive, position or contiguous gene effects may be associated in the etiopathogenesis of this autism-ID-epilepsy syndrome.
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Affiliation(s)
- Peter Wang
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
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Rare missense neuronal cadherin gene (CDH2) variants in specific obsessive-compulsive disorder and Tourette disorder phenotypes. Eur J Hum Genet 2013; 21:850-4. [PMID: 23321619 DOI: 10.1038/ejhg.2012.245] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 10/01/2012] [Accepted: 10/11/2012] [Indexed: 12/21/2022] Open
Abstract
The recent finding that the neuronal cadherin gene CDH2 confers a highly significant risk for canine compulsive disorder led us to investigate whether missense variants within the human ortholog CDH2 are associated with altered susceptibility to obsessive-compulsive disorder (OCD), Tourette disorder (TD) and related disorders. Exon resequencing of CDH2 in 320 individuals identified four non-synonymous single-nucleotide variants, which were subsequently genotyped in OCD probands, Tourette disorder probands and relatives, and healthy controls (total N=1161). None of the four variants was significantly associated with either OCD or TD. One variant, N706S, was found only in the OCD/TD groups, but not in controls. By examining clinical data, we found there were significant TD-related phenotype differences between those OCD probands with and without the N845S variant with regard to the co-occurrence of TD (Fisher's exact test P=0.014, OR=6.03). Both N706S and N845S variants conferred reduced CDH2 protein expression in transfected cells. Although our data provide no overall support for association of CDH2 rare variants in these disorders considered as single entities, the clinical features and severity of probands carrying the uncommon non-synonymous variants suggest that CDH2, along with other cadherin and cell adhesion genes, is an interesting gene to pursue as a plausible contributor to OCD, TD and related disorders with repetitive behaviors, including autism spectrum disorders.
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Chen A, Kelley LD, Janušonis S. Effects of prenatal stress and monoaminergic perturbations on the expression of serotonin 5-HT4 and adrenergic β2 receptors in the embryonic mouse telencephalon. Brain Res 2012; 1459:27-34. [DOI: 10.1016/j.brainres.2012.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 03/21/2012] [Accepted: 04/11/2012] [Indexed: 12/13/2022]
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Vincent AK, Noor A, Janson A, Minassian BA, Ayub M, Vincent JB, Morel CF. Identification of genomic deletions spanning the PCDH19 gene in two unrelated girls with intellectual disability and seizures. Clin Genet 2011; 82:540-5. [PMID: 22091964 DOI: 10.1111/j.1399-0004.2011.01812.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Recently, missense and truncating mutations in the gene PCDH19 have been reported to cause female-restricted epilepsy with mental retardation (EFMR). EFMR (MIM#300088) is an X-linked disorder characterized by early onset seizures and intellectual disability (ID). Interestingly, unlike typical X-linked mode of inheritance, the phenotype is restricted to females, and males are unaffected carriers. PCDH19 is highly expressed in brain, and the encoded protein belongs to the cadherin superfamily. Here we report two unrelated female patients with deletions spanning PCDH19 identified by copy number variation (CNV) analysis and validated by qPCR. In one, we have identified a 3 Mb interstitial deletion at Xq21.33-q22.1 which spans PCDH19, LOC442459 & TNMD. This patient had her first seizure at 8 months old, and also has ID and aggressive behavior. In another female patient we identified a de novo 603 kb heterozygous deletion in a female patient with fits (since 1 year of age), ID, hyperactivity and aggressive behavior. The deletion spans the entire PCDH19 gene (also TNMD, SRPX2, TSPAN6 and SYTL4). In conclusion, our results suggest that deletions at PCDH19 also cause EFMR.
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Affiliation(s)
- A K Vincent
- Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
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Hu VW, Addington A, Hyman A. Novel autism subtype-dependent genetic variants are revealed by quantitative trait and subphenotype association analyses of published GWAS data. PLoS One 2011; 6:e19067. [PMID: 21556359 PMCID: PMC3083416 DOI: 10.1371/journal.pone.0019067] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 03/18/2011] [Indexed: 01/26/2023] Open
Abstract
The heterogeneity of symptoms associated with autism spectrum disorders (ASDs) has presented a significant challenge to genetic analyses. Even when associations with genetic variants have been identified, it has been difficult to associate them with a specific trait or characteristic of autism. Here, we report that quantitative trait analyses of ASD symptoms combined with case-control association analyses using distinct ASD subphenotypes identified on the basis of symptomatic profiles result in the identification of highly significant associations with 18 novel single nucleotide polymorphisms (SNPs). The symptom categories included deficits in language usage, non-verbal communication, social development, and play skills, as well as insistence on sameness or ritualistic behaviors. Ten of the trait-associated SNPs, or quantitative trait loci (QTL), were associated with more than one subtype, providing partial replication of the identified QTL. Notably, none of the novel SNPs is located within an exonic region, suggesting that these hereditary components of ASDs are more likely related to gene regulatory processes (or gene expression) than to structural or functional changes in gene products. Seven of the QTL reside within intergenic chromosomal regions associated with rare copy number variants that have been previously reported in autistic samples. Pathway analyses of the genes associated with the QTL identified in this study implicate neurological functions and disorders associated with autism pathophysiology. This study underscores the advantage of incorporating both quantitative traits as well as subphenotypes into large-scale genome-wide analyses of complex disorders.
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Affiliation(s)
- Valerie W Hu
- Department of Biochemistry and Molecular Biology, The George Washington University Medical Center, Washington, DC, United States of America.
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