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Sund KL, Liu J, Lee J, Garbe J, Abdelhamed Z, Maag C, Hallinan B, Wu SW, Sperry E, Deshpande A, Stottmann R, Smolarek TA, Dyer LM, Hestand MS. Long-read sequencing and optical genome mapping identify causative gene disruptions in noncoding sequence in two patients with neurologic disease and known chromosome abnormalities. Am J Med Genet A 2024:e63818. [PMID: 39041659 DOI: 10.1002/ajmg.a.63818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 06/12/2024] [Accepted: 07/07/2024] [Indexed: 07/24/2024]
Abstract
Despite advances in next generation sequencing (NGS), genetic diagnoses remain elusive for many patients with neurologic syndromes. Long-read sequencing (LRS) and optical genome mapping (OGM) technologies improve upon existing capabilities in the detection and interpretation of structural variation in repetitive DNA, on a single haplotype, while also providing enhanced breakpoint resolution. We performed LRS and OGM on two patients with known chromosomal rearrangements and inconclusive Sanger or NGS. The first patient, who had epilepsy and developmental delay, had a complex translocation between two chromosomes that included insertion and inversion events. The second patient, who had a movement disorder, had an inversion on a single chromosome disrupted by multiple smaller inversions and insertions. Sequence level resolution of the rearrangements identified pathogenic breaks in noncoding sequence in or near known disease-causing genes with relevant neurologic phenotypes (MBD5, NKX2-1). These specific variants have not been reported previously, but expected molecular consequences are consistent with previously reported cases. As the use of LRS and OGM technologies for clinical testing increases and data analyses become more standardized, these methods along with multiomic data to validate noncoding variation effects will improve diagnostic yield and increase the proportion of probands with detectable pathogenic variants for known genes implicated in neurogenetic disease.
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Affiliation(s)
- Kristen L Sund
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jie Liu
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
| | - Joyce Lee
- Bionano Genomics, San Diego, California, USA
| | - John Garbe
- University of Minnesota Genomics Center, University of Minnesota, Minneapolis, Minnesota, USA
| | - Zakia Abdelhamed
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Chelsey Maag
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Barbara Hallinan
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Steven W Wu
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Ethan Sperry
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Archana Deshpande
- University of Minnesota Genomics Center, University of Minnesota, Minneapolis, Minnesota, USA
| | - Rolf Stottmann
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
| | - Teresa A Smolarek
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
| | - Lisa M Dyer
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
| | - Matthew S Hestand
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
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2
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Yang Q, Zhang Q, Yi S, Zhang S, Yi S, Zhou X, Qin Z, Chen B, Luo J. Novel germline variants in KMT2C in Chinese patients with Kleefstra syndrome-2. Front Neurol 2024; 15:1340458. [PMID: 38356881 PMCID: PMC10864639 DOI: 10.3389/fneur.2024.1340458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 01/10/2024] [Indexed: 02/16/2024] Open
Abstract
Kleefstra syndrome (KLEFS) refers to a rare inherited neurodevelopmental disorder characterized by intellectual disability (ID), language and motor delays, behavioral abnormalities, abnormal facial appearance, and other variable clinical features. KLEFS is subdivided into two subtypes: Kleefstra syndrome-1 (KLEFS1, OMIM: 610253), caused by a heterozygous microdeletion encompassing the Euchromatic Histone Lysine Methyltransferase 1 (EHMT1) gene on chromosome 9q34.3 or pathogenic variants in the EHMT1 gene, and Kleefstra syndrome-2 (KLEFS2, OMIM: 617768), caused by pathogenic variants in the KMT2C gene. More than 100 cases of KLEFS1 have been reported with pathogenic variants in the EHMT1 gene. However, only 13 patients with KLEFS2 have been reported to date. In the present study, five unrelated Chinese patients were diagnosed with KLEFS2 caused by KMT2C variants through whole-exome sequencing (WES). We identified five different variants of the KMT2C gene in these patients: c.9166C>T (p.Gln3056*), c.9232_9247delCAGCGATCAGAACCGT (p.Gln3078fs*13), c.5068dupA (p.Arg1690fs*10), c.10815_10819delAAGAA (p.Lys3605fs*7), and c.6911_6912insA (p.Met2304fs*8). All five patients had a clinical profile similar to that of patients with KLEFS2. To analyze the correlation between the genotype and phenotype of KLEFS2, we examined 18 variants and their associated phenotypes in 18 patients with KLEFS2. Patients carrying KMT2C variants presented with a wide range of phenotypic defects and an extremely variable phenotype. We concluded that the core phenotypes associated with KMT2C variants were intellectual disability, facial dysmorphisms, language and motor delays, behavioral abnormalities, hypotonia, short stature, and weight loss. Additionally, sex may be one factor influencing the outcome. Our findings expand the phenotypic and genetic spectrum of KLEFS2 and help to clarify the genotype-phenotype correlation.
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Affiliation(s)
- Qi Yang
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Qiang Zhang
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Sheng Yi
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Shujie Zhang
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Shang Yi
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Xunzhao Zhou
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Zailong Qin
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Biyan Chen
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Jingsi Luo
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Guangxi Clinical Research Center for Pediatric Diseases, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
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3
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Azmerin M, Hussain MS, Aziz MA, Barek MA, Begum M, Sen N, Rahman MA, Shahriar M, Baeesa SS, Ashraf GM, Islam MS. TF and TCF4 gene polymorphisms are linked to autism spectrum disorder: a case-control study. J Int Med Res 2022; 50:3000605221138492. [PMID: 36448207 PMCID: PMC9716618 DOI: 10.1177/03000605221138492] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
OBJECTIVE Although the prevalence of autism spectrum disorder (ASD) is increasing, appropriate diagnosis and prevention strategies are still lacking. This case-control study was designed to explore the association between ASD and the rs1867503 and rs9951150 polymorphisms of the TF and TCF4 genes, respectively. METHODS Ninety-six children with ASD and 118 healthy children were recruited and polymerase chain reaction-restriction fragment length polymorphism technique was applied for genotyping. RESULTS The frequencies of the mutant allele G were 48% and 44% for the rs1867503 and rs9951150 polymorphisms, respectively. In our analysis, both TF and TCF4 polymorphisms were associated with an increased risk of developing ASD. AG heterozygotes (OR = 3.18), GG mutant homozygotes (OR = 2.62), AG + GG combined genotypes (OR = 2.98), and G mutant alleles of TF rs1867503 (OR = 1.94) were associated with a significantly elevated risk of ASD. Likewise, AG heterozygotes (OR = 2.92), GG mutant homozygotes (OR = 2.36), AG + GG combined genotypes (OR = 2.72), and G minor alleles of TCF4 rs9951150 (OR = 1.92) were associated with a significantly elevated risk of ASD. CONCLUSIONS Our results indicate that TF rs1867503 and TCF4 rs9951150 polymorphisms may be strongly associated with the development of ASD in Bangladeshi children.
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Affiliation(s)
- Maria Azmerin
- Department of Pharmacy, University of Asia Pacific, Dhaka, Bangladesh
| | - Md. Saddam Hussain
- Department of Pharmacy, Faculty of Science, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh,Laboratory of Pharmacogenomics and Molecular Biology, Department of Pharmacy, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh
| | - Md. Abdul Aziz
- Department of Pharmacy, Faculty of Science, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh,Laboratory of Pharmacogenomics and Molecular Biology, Department of Pharmacy, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh
| | - Md. Abdul Barek
- Department of Pharmacy, Faculty of Science, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh,Laboratory of Pharmacogenomics and Molecular Biology, Department of Pharmacy, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh
| | - Mobashera Begum
- Department of Pharmacy, Faculty of Science, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh,Laboratory of Pharmacogenomics and Molecular Biology, Department of Pharmacy, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh
| | - Niloy Sen
- Department of Pharmacy, Faculty of Science, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh,Laboratory of Pharmacogenomics and Molecular Biology, Department of Pharmacy, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh
| | - Md. Abdur Rahman
- Department of Pharmacy, Faculty of Science, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh
| | - Mohammad Shahriar
- Department of Pharmacy, University of Asia Pacific, Dhaka, Bangladesh
| | - Saleh Salem Baeesa
- Division of Neurosurgery, College of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ghulam Md Ashraf
- Department of Medical Laboratory Sciences, College of Health Sciences, University of Sharjah, University City, United Arab Emirates
| | - Mohammad Safiqul Islam
- Department of Pharmacy, Faculty of Science, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh,Laboratory of Pharmacogenomics and Molecular Biology, Department of Pharmacy, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh,Mohammad Safiqul Islam, Department of Pharmacy, Noakhali Science and Technology University, Sonapur-3814, Noakhali, Bangladesh.
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4
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Retinoic acid-induced 1 gene haploinsufficiency alters lipid metabolism and causes autophagy defects in Smith-Magenis syndrome. Cell Death Dis 2022; 13:981. [PMID: 36411275 PMCID: PMC9678881 DOI: 10.1038/s41419-022-05410-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/28/2022] [Accepted: 11/04/2022] [Indexed: 11/22/2022]
Abstract
Smith-Magenis syndrome (SMS) is a neurodevelopmental disorder characterized by cognitive and behavioral symptoms, obesity, and sleep disturbance, and no therapy has been developed to alleviate its symptoms or delay disease onset. SMS occurs due to haploinsufficiency of the retinoic acid-induced-1 (RAI1) gene caused by either chromosomal deletion (SMS-del) or RAI1 missense/nonsense mutation. The molecular mechanisms underlying SMS are unknown. Here, we generated and characterized primary cells derived from four SMS patients (two with SMS-del and two carrying RAI1 point mutations) and four control subjects to investigate the pathogenetic processes underlying SMS. By combining transcriptomic and lipidomic analyses, we found altered expression of lipid and lysosomal genes, deregulation of lipid metabolism, accumulation of lipid droplets, and blocked autophagic flux. We also found that SMS cells exhibited increased cell death associated with the mitochondrial pathology and the production of reactive oxygen species. Treatment with N-acetylcysteine reduced cell death and lipid accumulation, which suggests a causative link between metabolic dyshomeostasis and cell viability. Our results highlight the pathological processes in human SMS cells involving lipid metabolism, autophagy defects and mitochondrial dysfunction and suggest new potential therapeutic targets for patient treatment.
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5
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Rinaldi B, Villa R, Sironi A, Garavelli L, Finelli P, Bedeschi MF. Smith-Magenis Syndrome—Clinical Review, Biological Background and Related Disorders. Genes (Basel) 2022; 13:genes13020335. [PMID: 35205380 PMCID: PMC8872351 DOI: 10.3390/genes13020335] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/03/2022] [Accepted: 02/08/2022] [Indexed: 02/06/2023] Open
Abstract
Smith-Magenis syndrome (SMS) is a complex genetic disorder characterized by distinctive physical features, developmental delay, cognitive impairment, and a typical behavioral phenotype. SMS is caused by interstitial 17p11.2 deletions (90%), encompassing multiple genes and including the retinoic acid-induced 1 gene (RAI1), or by pathogenic variants in RAI1 itself (10%). RAI1 is a dosage-sensitive gene expressed in many tissues and acting as transcriptional regulator. The majority of individuals exhibit a mild-to-moderate range of intellectual disability. The behavioral phenotype includes significant sleep disturbance, stereotypes, maladaptive and self-injurious behaviors. In this review, we summarize current clinical knowledge and therapeutic approaches. We further discuss the common biological background shared with other conditions commonly retained in differential diagnosis.
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Affiliation(s)
- Berardo Rinaldi
- Clinical Genetics Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (B.R.); (R.V.)
| | - Roberta Villa
- Clinical Genetics Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (B.R.); (R.V.)
| | - Alessandra Sironi
- Experimental Research Laboratory of Medical Cytogenetics and Molecular Genetics, Istituto Auxologico Italiano, IRCCS, 20145 Milan, Italy; (A.S.); (P.F.)
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Segrate, 20090 Milan, Italy
| | - Livia Garavelli
- Clinical Genetics Unit, Azienda USL-IRCCS of Reggio Emilia, 42123 Reggio Emilia, Italy;
| | - Palma Finelli
- Experimental Research Laboratory of Medical Cytogenetics and Molecular Genetics, Istituto Auxologico Italiano, IRCCS, 20145 Milan, Italy; (A.S.); (P.F.)
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Segrate, 20090 Milan, Italy
| | - Maria Francesca Bedeschi
- Clinical Genetics Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (B.R.); (R.V.)
- Correspondence:
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6
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Chen CH, Cheng MC, Hu TM, Ping LY. Chromosomal Microarray Analysis as First-Tier Genetic Test for Schizophrenia. Front Genet 2021; 12:620496. [PMID: 34659328 PMCID: PMC8517076 DOI: 10.3389/fgene.2021.620496] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 09/20/2021] [Indexed: 01/07/2023] Open
Abstract
Schizophrenia is a chronic, devastating mental disorder with complex genetic components. Given the advancements in the molecular genetic research of schizophrenia in recent years, there is still a lack of genetic tests that can be used in clinical settings. Chromosomal microarray analysis (CMA) has been used as first-tier genetic testing for congenital abnormalities, developmental delay, and autism spectrum disorders. This study attempted to gain some experience in applying chromosomal microarray analysis as a first-tier genetic test for patients with schizophrenia. We consecutively enrolled patients with schizophrenia spectrum disorder from a clinical setting and conducted genome-wide copy number variation (CNV) analysis using a chromosomal microarray platform. We followed the 2020 “Technical Standards for the interpretation and reporting of constitutional copy-number variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics (ACMG) and the Clinical Genome Resource (ClinGen)” to interpret the clinical significance of CNVs detected from patients. We recruited a total of 60 patients (36 females and 24 males) into this study. We detected three pathogenic CNVs and one likely pathogenic CNV in four patients, respectively. The detection rate was 6.7% (4/60, 95% CI: 0.004–0.13), comparable with previous studies in the literature. Also, we detected thirteen CNVs classified as uncertain clinical significance in nine patients. Detecting these CNVs can help establish the molecular genetic diagnosis of schizophrenia patients and provide helpful information for genetic counseling and clinical management. Also, it can increase our understanding of the pathogenesis of schizophrenia. Hence, we suggest CMA is a valuable genetic tool and considered first-tier genetic testing for schizophrenia spectrum disorders in clinical settings.
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Affiliation(s)
- Chia-Hsiang Chen
- Department of Psychiatry, Chang Gung Memorial Hospital, Taoyuan, Taiwan.,Department and Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Min-Chih Cheng
- Department of Psychiatry, Yuli Branch, Taipei Veterans General Hospital, Hualien, Taiwan
| | - Tsung-Ming Hu
- Department of Psychiatry, Yuli Branch, Taipei Veterans General Hospital, Hualien, Taiwan
| | - Lieh-Yung Ping
- Department of Psychiatry, Yuli Branch, Taipei Veterans General Hospital, Hualien, Taiwan
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7
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González-Ortega G, Llamas-Velasco S, Arteche-López A, Quesada-Espinosa JF, Puertas-Martín V, Gómez-Grande A, López-Álvarez J, Saiz Díaz RA, Lezana-Rosales JM, Villarejo-Galende A, González de la Aleja J. Early-Onset Dementia Associated with a Heterozygous, Nonsense, and de novo Variant in the MBD5 Gene. J Alzheimers Dis 2021; 84:73-78. [PMID: 34459404 DOI: 10.3233/jad-210648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The haploinsufficiency of the methyl-binding domain protein 5 (MBD5) gene has been identified as the determinant cause of the neuropsychiatric disorders grouped under the name MBD5-neurodevelopment disorders (MAND). MAND includes patients with intellectual disability, behavioral problems, and seizures with a static clinical course. However, a few reports have suggested regression. We describe a non-intellectually disabled female, with previous epilepsy and personality disorder, who developed early-onset dementia. The extensive etiologic study revealed a heterozygous nonsense de novo pathogenic variant in the MBD5 gene. This finding could support including the MBD5 gene in the study of patients with atypical early-onset dementia.
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Affiliation(s)
| | - Sara Llamas-Velasco
- Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain.,Group of Neurodegenerative Diseases, Instituto de Investigación Hospital 12 de Octubre (I+12), Madrid, Spain.,Biomedical Research Networking Center in Neurodegenerative diseases CIBERNED, Madrid, Spain
| | - Ana Arteche-López
- Department of Genetics, Hospital Universitario 12 de Octubre, Madrid, Spain
| | | | - Verónica Puertas-Martín
- Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain.,Universidad Internacional de La Rioja (UNIR), Logroño, Spain
| | - Adolfo Gómez-Grande
- Department of Nuclear Medicine, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Jorge López-Álvarez
- Department of Psychiatry, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Rosa Ana Saiz Díaz
- Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain.,Department of Medicine, School of Medicine, Complutense University, Madrid, Spain.,Epilepsy-EEG Unit, Hospital Universitario 12 de Octubre, Madrid, Spain
| | | | - Alberto Villarejo-Galende
- Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain.,Group of Neurodegenerative Diseases, Instituto de Investigación Hospital 12 de Octubre (I+12), Madrid, Spain.,Biomedical Research Networking Center in Neurodegenerative diseases CIBERNED, Madrid, Spain.,Department of Medicine, School of Medicine, Complutense University, Madrid, Spain
| | - Jesús González de la Aleja
- Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain.,Epilepsy-EEG Unit, Hospital Universitario 12 de Octubre, Madrid, Spain
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8
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Mullegama SV, Klein SD, Williams SR, Innis JW, Probst FJ, Haldeman-Englert C, Martinez-Agosto JA, Yang Y, Tian Y, Elsea SH, Ezashi T. Transcriptome analysis of MBD5-associated neurodevelopmental disorder (MAND) neural progenitor cells reveals dysregulation of autism-associated genes. Sci Rep 2021; 11:11295. [PMID: 34050248 PMCID: PMC8163803 DOI: 10.1038/s41598-021-90798-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 04/20/2021] [Indexed: 11/30/2022] Open
Abstract
MBD5-associated neurodevelopmental disorder (MAND) is an autism spectrum disorder (ASD) characterized by intellectual disability, motor delay, speech impairment and behavioral problems; however, the biological role of methyl-CpG-binding domain 5, MBD5, in neurodevelopment and ASD remains largely undefined. Hence, we created neural progenitor cells (NPC) derived from individuals with chromosome 2q23.1 deletion and conducted RNA-seq to identify differentially expressed genes (DEGs) and the biological processes and pathways altered in MAND. Primary skin fibroblasts from three unrelated individuals with MAND and four unrelated controls were converted into induced pluripotent stem cell (iPSC) lines, followed by directed differentiation of iPSC to NPC. Transcriptome analysis of MAND NPC revealed 468 DEGs (q < 0.05), including 20 ASD-associated genes. Comparison of DEGs in MAND with SFARI syndromic autism genes revealed a striking significant overlap in biological processes commonly altered in neurodevelopmental phenotypes, with TGFβ, Hippo signaling, DNA replication, and cell cycle among the top enriched pathways. Overall, these transcriptome deviations provide potential connections to the overlapping neurocognitive and neuropsychiatric phenotypes associated with key high-risk ASD genes, including chromatin modifiers and epigenetic modulators, that play significant roles in these disease states.
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Affiliation(s)
- Sureni V Mullegama
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Department of Molecular and Cellular Biology, College of Osteopathic Medicine, Sam Houston State University, Conroe, TX, 77304, USA
| | - Steven D Klein
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Medical Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | | | - Jeffrey W Innis
- Departments of Human Genetics, Pediatrics and Internal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Frank J Probst
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | | | - Julian A Martinez-Agosto
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ying Yang
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, 33612, USA
| | - Yuchen Tian
- Division of Animal Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
| | - Toshihiko Ezashi
- Division of Animal Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA.
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9
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Ziats CA, Patterson WG, Friez M. Syndromic Autism Revisited: Review of the Literature and Lessons Learned. Pediatr Neurol 2021; 114:21-25. [PMID: 33189026 DOI: 10.1016/j.pediatrneurol.2020.06.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/01/2020] [Accepted: 06/19/2020] [Indexed: 11/29/2022]
Abstract
Autism spectrum disorder is a neurodevelopmental disorder characterized by deficits in communication, stereotyped behaviors, restricted interests, and impaired social skills. The severity of the neurobehavioral phenotype is variable and historically has been distinguished based on the presence or absence of additional symptoms, termed syndromic and nonsyndromic or idiopathic autism, respectively. However, although the advancement in genetic molecular technologies has brought an increased understanding of the pathophysiology of autism, most of this success has been in the diagnosis of syndromic disease, whereas the etiology of nonsyndromic autism remains less understood. Here we review the common and rare genetic syndromes that feature autism, specifically highlighting deletion and duplication syndromes, chromosomal anomalies, and monogenic disorders. We show that the study of syndromic autism provides insight into the phenotypic and molecular heterogeneity of neurodevelopmental disease and suggests how study of these disorders can be helpful in understanding disease mechanisms implicated in nonsyndromic autism.
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Affiliation(s)
- Catherine A Ziats
- Greenwood Genetic Center, J.C. Self Research Institute, Greenwood, South Carolina.
| | - Wesley G Patterson
- Greenwood Genetic Center, J.C. Self Research Institute, Greenwood, South Carolina
| | - Michael Friez
- Greenwood Genetic Center, J.C. Self Research Institute, Greenwood, South Carolina
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10
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Verhoeven W, Egger J, Kipp J, Verheul‐ aan de Wiel J, Ockeloen C, Kleefstra T, Pfundt R. A novel MBD5 mutation in an intellectually disabled adult female patient with epilepsy: Suggestive of early onset dementia? Mol Genet Genomic Med 2019; 7:e849. [PMID: 31290275 PMCID: PMC6687664 DOI: 10.1002/mgg3.849] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 05/27/2019] [Accepted: 06/05/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The minimal critical region in 2q23.1 deletion syndrome comprises one gene only, that is, the methyl-CpG-binding domain protein 5 (MBD5) gene. Since the phenotypes of patients with deletions, duplications or pathogenic variants of MBD5 show considerable overlap, the term MBD5-associated neurodevelopmental disorder (MAND) was proposed. These syndromes are characterized by intellectual disability, seizures of any kind and symptoms from the autism spectrum. In a very limited number of patients, MAND may be associated with regression starting either at early infancy or at midlife. METHODS The present paper describes a severely intellectually disabled autistic female with therapy resistant complex partial epilepsy starting at her 16the with gradual cognitive and behavioral regression towards her sixth decade. RESULTS Cognitive and behavioral regression occurred towards the patient's sixth decade. Exome sequencing disclosed a novel heterozygous pathogenic frameshift mutation of MBD5 that was considered to be causative for the combination of intellectual disability, treatment-resistant epilepsy and autism. CONCLUSION The presented patient is the second with a pathogenic MBD5 mutation in whom the course of disease is suggestive of early onset dementia starting in her fifth decade. These findings stress the importance of exome sequencing, also in elderly intellectually disabled patients, particularly in those with autism.
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Affiliation(s)
- Willem Verhoeven
- Centre of Excellence for NeuropsychiatryVincent van Gogh Institute for PsychiatryVenraythe Netherlands
- Department of PsychiatryErasmus University Medical CentreRotterdamthe Netherlands
| | - Jos Egger
- Centre of Excellence for NeuropsychiatryVincent van Gogh Institute for PsychiatryVenraythe Netherlands
- Donders Institute for Brain, Cognition and BehaviourRadboud UniversityNijmegenthe Netherlands
- Stevig Specialized and Forensic Care for People with Intellectual Disabilities, DichterbijOostrumthe Netherlands
| | - Janneke Kipp
- ASVZ Institutes for Intellectual DisabilitiesLeerdamthe Netherlands
| | | | - Charlotte Ockeloen
- Department of Human GeneticsRadboud University Medical CenterNijmegenthe Netherlands
| | - Tjitske Kleefstra
- Department of Human GeneticsRadboud University Medical CenterNijmegenthe Netherlands
| | - Rolph Pfundt
- Department of Human GeneticsRadboud University Medical CenterNijmegenthe Netherlands
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11
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Venkatapoorna CMK, Ayine P, Parra EP, Koenigs T, Phillips M, Babu JR, Sandey M, Geetha T. Association of Salivary Amylase ( AMY1) Gene Copy Number with Obesity in Alabama Elementary School Children. Nutrients 2019; 11:nu11061379. [PMID: 31248128 PMCID: PMC6627241 DOI: 10.3390/nu11061379] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/16/2019] [Accepted: 06/17/2019] [Indexed: 01/14/2023] Open
Abstract
Salivary amylase (AMY1) is the most abundant enzyme in human saliva, responsible for the hydrolysis of α-1,4 glycosidic linkages that aids in the digestion of starch. Recently studies have shown that the copy number of AMY1 is associated with obesity; however, the data varies with location. One-third of children are overweight/obese in Alabama. In this study, we aim to determine the relationship between the copy number of AMY1 gene and obesity measurements in children from Alabama. One hundred twenty-seven children aged between 6 to 10 years participated in this study. Anthropometric measurements were measured using WHO recommendations. Genomic DNA was extracted from saliva, and the copy number of the AMY1 gene was estimated by digital PCR. The association between AMY1 copy number and obesity measurements was analyzed by linear regression. The mean AMY1 copy number significantly decreased in overweight/obese (6.21 ± 1.48) compared to normal weight (7.97 ± 2.35) children. AMY1 copy number inversely associated with the obesity measurements. African Americans had a stronger association between low AMY1 copy number and obesity compared to white/European Americans. Our findings suggest that overweight/obese children have a low AMY1 copy number and the effect is more prominent in African Americans.
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Affiliation(s)
- Chandra M K Venkatapoorna
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA.
| | - Priscilla Ayine
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA.
| | - Emily P Parra
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA.
| | - Taylor Koenigs
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA.
| | - Megan Phillips
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA.
| | - Jeganathan R Babu
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA.
- Boshell Metabolic Diseases and Diabetes Program, Auburn University, Auburn, AL 36849, USA.
| | - Maninder Sandey
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA.
| | - Thangiah Geetha
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA.
- Boshell Metabolic Diseases and Diabetes Program, Auburn University, Auburn, AL 36849, USA.
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12
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Wang DX, Kaur Y, Alyass A, Meyre D. A Candidate-Gene Approach Identifies Novel Associations Between Common Variants in/Near Syndromic Obesity Genes and BMI in Pediatric and Adult European Populations. Diabetes 2019; 68:724-732. [PMID: 30692245 DOI: 10.2337/db18-0986] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/24/2019] [Indexed: 11/13/2022]
Abstract
We hypothesized that monogenic syndromic obesity genes are also involved in the polygenic variation of BMI. Single-marker, tag single nucleotide polymorphism (tagSNP) and gene-based analysis were performed on common variants near 54 syndromic obesity genes. We used publicly available data from meta-analyses of European BMI genome-wide association studies conducted by the Genetic Investigation of ANthropometric Traits (GIANT) Consortium and the UK Biobank (UKB) (N = 681,275 adults). A total of 33 loci were identified, of which 19 of 33 (57.6%) were located at SNPs previously identified by the GIANT Consortium and UKB meta-analysis, 11 of 33 (33.3%) were located at novel SNPs, and 3 of 33 (9.1%) were novel genes identified with gene-based analysis. Both single-marker and tagSNP analyses mapped the previously identified 19 SNPs by the GIANT Consortium and UKB meta-analysis. Gene-based analysis confirmed 15 of 19 (78.9%) of the novel SNPs' associated genes. Of the 11 novel loci, 8 were identified with single-marker analysis and the remaining 3 were identified with tagSNP analysis. Gene-based analysis confirmed 4 of 11 (36.3%) of these loci. Meta-analysis with the Early Growth Genetics (EGG) Consortium (N = 35,668 children) was conducted post hoc for top SNPs, confirming 17 of 33 (51.5%) loci, of which 5 were novel. This study supports evidence for a continuum between rare monogenic syndromic and common polygenic forms of obesity.
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Affiliation(s)
- Dominic X Wang
- Department of Health Research, Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
- Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Yuvreet Kaur
- Department of Health Research, Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Akram Alyass
- Department of Health Research, Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - David Meyre
- Department of Health Research, Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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13
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Le TN, Williams SR, Alaimo JT, Elsea SH. Genotype and phenotype correlation in 103 individuals with 2q37 deletion syndrome reveals incomplete penetrance and supports HDAC4 as the primary genetic contributor. Am J Med Genet A 2019; 179:782-791. [PMID: 30848064 DOI: 10.1002/ajmg.a.61089] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 01/02/2019] [Accepted: 02/05/2019] [Indexed: 12/11/2022]
Abstract
The 2q37 deletion syndrome, also described in the literature as brachydactyly-mental retardation syndrome (MIM 600430), is caused by deletion or haploinsufficiency of the HDAC4 gene, which encodes the histone deacetylase 4 protein. Although the most commonly described hallmark features of the 2q37 deletion syndrome include brachydactyly type E, developmental delay, obesity, autistic features, and craniofacial or skeletal dysmorphism, a literature review of 101 published cases plus two newly reported individuals indicates that there is a high degree of variability in the presence of some of the features that are considered the most characteristic of the syndrome: overweight and obesity (34%), cognitive-behavioral issues (79%), dysmorphic craniofacial features (86%), and type E brachydactyly (48%). These features overlap with other neurodevelopmental conditions, including Smith-Magenis syndrome (SMS), and may be incompletely penetrant or demonstrate variable expressivity, depending on the specific chromosomal anomaly. With the advent of fluorescence in situ hybridization (FISH), array-based comparative genomic hybridization, and next-generation DNA sequencing, more detailed molecular diagnoses are possible than in years past, enabling refined characterization of the genotype-phenotype correlation for subjects with 2q37 deletions. In addition, investigations into molecular and gene expression networks are expanding in neurodevelopmental conditions, and we surveyed HDAC4 downstream gene expression by quantitative real-time polymerase chain reaction, further implicating HDAC4 in its role in the regulation of RAI1. Correlation of clinical data defining the impact on downstream gene expression and the potential clinical associations across neurodevelopment will improve our understanding of these complex conditions and potentially lead to common therapeutic approaches.
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Affiliation(s)
- Trang N Le
- Department of Pediatrics, Virginia Commonwealth University School of Medicine, Richmond, Virginia.,Department of Internal Medicine, Division of Endocrinology, Virginia Commonwealth University School of Medicine, Richmond, Virginia
| | - Stephen R Williams
- Department of Neurology, University of Virginia, Charlottesville, Virginia
| | - Joseph T Alaimo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Sarah H Elsea
- Department of Pediatrics, Virginia Commonwealth University School of Medicine, Richmond, Virginia.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, Virginia
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14
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Carmassi C, Palagini L, Caruso D, Masci I, Nobili L, Vita A, Dell'Osso L. Systematic Review of Sleep Disturbances and Circadian Sleep Desynchronization in Autism Spectrum Disorder: Toward an Integrative Model of a Self-Reinforcing Loop. Front Psychiatry 2019; 10:366. [PMID: 31244687 PMCID: PMC6581070 DOI: 10.3389/fpsyt.2019.00366] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/13/2019] [Indexed: 12/13/2022] Open
Abstract
Background: A compelling number of studies, conducted in both children and adults, have reported an association between sleep disturbances/circadian sleep alterations and autism spectrum disorder (ASD); however, the data are sparse and the nature of this link is still unclear. The present review aimed to systematically collect the literature data relevant on sleep disturbances and circadian sleep dysrhythmicity related to ASD across all ages and to provide an integrative theoretical framework of their association. Methods: A systematic review of the MEDLINE, PubMed, and Cochrane databases was conducted from November 2018 to February 2019. The search strategies used were MeSH headings and keywords for "sleep-wake circadian rhythms" OR "circadian sleep disorders" OR "sleep-wake pattern" OR "sleep disorders" OR "melatonin" AND "autism spectrum disorder" OR "autism". Results: One hundred and three studies were identified, 15 regarded circadian sleep dysrhythmicity, 74 regarded sleep disturbances, and 17 regarded melatonin alterations in children and adults with ASD. Our findings suggested that autistic subjects frequently present sleep disturbances in particular short sleep duration, low sleep quality/efficiency, and circadian sleep desynchronization such as delayed phases and/or eveningness. Sleep disturbances and circadian sleep alterations have been related to the severity of autistic symptoms. Genetic studies have shown polymorphisms in circadian CLOCK genes and in genes involved in melatonin pathways in subjects with ASD. Conclusions: Sleep disturbances and circadian sleep alterations are frequent in subjects with autistic symptoms. These subjects have shown polymorphisms in clock genes expression and in genes involved in melatonin production. The impairment of circadian sleep regulation may increase the individual's vulnerability to develop symptoms of ASD by altering the sleep regulation in toto, which plays a key role in normal brain development. Even though controversies and "research gaps" are present in literature at this point, we may hypothesize a bidirectional relation between circadian sleep dysfunction and ASD. In particular, circadian sleep dysrhythmicity may predispose to develop ASD symptoms and vice versa within a self-reinforcing feedback loop. By targeting sleep disturbances and circadian sleep dysrhythmicity, we may improve treatment strategies for both children and adults with ASD.
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Affiliation(s)
- Claudia Carmassi
- Department of Clinical and Experimental Medicine, Psychiatry Division, University of Pisa, Pisa, Italy
| | - Laura Palagini
- Department of Clinical and Experimental Medicine, Psychiatry Division, University of Pisa, Pisa, Italy
| | - Danila Caruso
- Department of Clinical and Experimental Medicine, Psychiatry Division, University of Pisa, Pisa, Italy
| | - Isabella Masci
- Department of Clinical and Experimental Medicine, Psychiatry Division, University of Pisa, Pisa, Italy
| | - Lino Nobili
- Child Neuropsychiatry Unit, IRCCS G. Gaslini Institute, Genova, Italy.,Department of Neuroscience-Rehabilitation-Ophthalmology-Genetics-Child and Maternal Health (DINOGMI), University of Genova, Genova, Italy
| | - Antonio Vita
- Psychiatry Division, Department of Clinical and Experimental Medicine, University of Brescia, Brescia, Italy
| | - Liliana Dell'Osso
- Department of Clinical and Experimental Medicine, Psychiatry Division, University of Pisa, Pisa, Italy
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15
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Fernandez BA, Scherer SW. Syndromic autism spectrum disorders: moving from a clinically defined to a molecularly defined approach. DIALOGUES IN CLINICAL NEUROSCIENCE 2018. [PMID: 29398931 PMCID: PMC5789213 DOI: 10.31887/dcns.2017.19.4/sscherer] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Autism spectrum disorder (ASD) encompasses a group of neurodevelopmental conditions diagnosed solely on the basis of behavioral assessments that reveal social deficits. Progress has been made in understanding its genetic underpinnings, but most ASD-associated genetic variants, which include copy number variants (CNVs) and mutations in ASD-risk genes, account for no more than 1 % of ASD cases. This high level of genetic heterogeneity leads to challenges obtaining and interpreting genetic testing in clinical settings. The traditional definition of syndromic ASD is a disorder with a clinically defined pattern of somatic abnormalities and a neurobehavioral phenotype that may include ASD. Most have a known genetic cause. Examples include fragile X syndrome and tuberous sclerosis complex. We propose dividing syndromic autism into the following two groups: (i) ASD that occurs in the context of a clinically defined syndrome-recognizing these disorders depends on the familiarity of the clinician with the features of the syndrome, and the diagnosis is typically confirmed by targeted genetic testing (eg, mutation screening of FMR1); (ii) ASD that occurs as a feature of a molecularly defined syndrome-for this group of patients, ASD-associated variants are identified by genome-wide testing that is not hypothesis driven (eg, microarray, whole exome sequencing). These ASD groups cannot be easily clinically defined because patients with a given variant have variable somatic abnormalities (dysmorphism and birth defects). In this article, we review common diagnoses from the above categories and suggest a testing strategy for patients, guided by determining whether the individual has essential or complex ASD; patients in the latter group have multiple morphologic anomalies on physical examination. Finally, we recommend that the syndromic versus nonsyndromic designation ultimately be replaced by classification of ASD according to its genetic etiology, which will inform about the associated spectrum and penetrance of neurobehavioral and somatic manifestations.
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Affiliation(s)
- Bridget A Fernandez
- Disciplines of Genetics and Medicine, Faculty of Medicine, Memorial University of Newfoundland, St John's, NL Canada
| | - Stephen W Scherer
- The Center for Applied Genomics and Program in Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario, Canada; McLaughlin Center and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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16
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Larizza L, Finelli P. Developmental disorders with intellectual disability driven by chromatin dysregulation: Clinical overlaps and molecular mechanisms. Clin Genet 2018; 95:231-240. [DOI: 10.1111/cge.13365] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/28/2018] [Accepted: 04/14/2018] [Indexed: 12/30/2022]
Affiliation(s)
- L. Larizza
- Laboratory of Cytogenetics and Molecular Genetics; Istituto Auxologico Italiano; Milan Italy
| | - P. Finelli
- Laboratory of Cytogenetics and Molecular Genetics; Istituto Auxologico Italiano; Milan Italy
- Department of Medical Biotechnology and Translational Medicine; Università degli Studi di Milano; Milan Italy
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17
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Page SC, Hamersky GR, Gallo RA, Rannals MD, Calcaterra NE, Campbell MN, Mayfield B, Briley A, Phan BN, Jaffe AE, Maher BJ. The schizophrenia- and autism-associated gene, transcription factor 4 regulates the columnar distribution of layer 2/3 prefrontal pyramidal neurons in an activity-dependent manner. Mol Psychiatry 2018; 23:304-315. [PMID: 28289282 PMCID: PMC5599320 DOI: 10.1038/mp.2017.37] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 01/05/2017] [Accepted: 01/26/2017] [Indexed: 01/18/2023]
Abstract
Disruption of the laminar and columnar organization of the brain is implicated in several psychiatric disorders. Here, we show in utero gain-of-function of the psychiatric risk gene transcription factor 4 (TCF4) severely disrupts the columnar organization of medial prefrontal cortex (mPFC) in a transcription- and activity-dependent manner. This morphological phenotype was rescued by co-expression of TCF4 plus calmodulin in a calcium-dependent manner and by dampening neuronal excitability through co-expression of an inwardly rectifying potassium channel (Kir2.1). For we believe the first time, we show that N-methyl-d-aspartate (NMDA) receptor-dependent Ca2+ transients are instructive to minicolumn organization because Crispr/Cas9-mediated mutation of NMDA receptors rescued TCF4-dependent morphological phenotypes. Furthermore, we demonstrate that the transcriptional regulation by the psychiatric risk gene TCF4 enhances NMDA receptor-dependent early network oscillations. Our novel findings indicate that TCF4-dependent transcription directs the proper formation of prefrontal cortical minicolumns by regulating the expression of genes involved in early spontaneous neuronal activity, and thus our results provides insights into potential pathophysiological mechanisms of TCF4-associated psychiatric disorders.
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Affiliation(s)
| | - Gregory R. Hamersky
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Ryan A. Gallo
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Matthew D. Rannals
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | | | - Morganne N. Campbell
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Brent Mayfield
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Aaron Briley
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - BaDoi N. Phan
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Andrew E. Jaffe
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD,Department of Biostatistics and Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Brady J. Maher
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD,Department of Psychiatry and Behavioral Sciences and Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD,To Whom Correspondence Should Be Addressed: Brady J. Maher, Ph. D., Lieber Institute for Brain Development, 855 N. Wolfe Street, Suite 300, Baltimore, MD 21205, Telephone: 410-955-0865, Fax: 410-955-1044,
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18
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Fernandez BA. Syndromic autism spectrum disorders: moving from a clinically defined to a molecularly defined approach. DIALOGUES IN CLINICAL NEUROSCIENCE 2017; 19:353-371. [PMID: 29398931 PMCID: PMC5789213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Autism spectrum disorder (ASD) encompasses a group of neurodevelopmental conditions diagnosed solely on the basis of behavioral assessments that reveal social deficits. Progress has been made in understanding its genetic underpinnings, but most ASD-associated genetic variants, which include copy number variants (CNVs) and mutations in ASD-risk genes, account for no more than 1 % of ASD cases. This high level of genetic heterogeneity leads to challenges obtaining and interpreting genetic testing in clinical settings. The traditional definition of syndromic ASD is a disorder with a clinically defined pattern of somatic abnormalities and a neurobehavioral phenotype that may include ASD. Most have a known genetic cause. Examples include fragile X syndrome and tuberous sclerosis complex. We propose dividing syndromic autism into the following two groups: (i) ASD that occurs in the context of a clinically defined syndrome-recognizing these disorders depends on the familiarity of the clinician with the features of the syndrome, and the diagnosis is typically confirmed by targeted genetic testing (eg, mutation screening of FMR1); (ii) ASD that occurs as a feature of a molecularly defined syndrome-for this group of patients, ASD-associated variants are identified by genome-wide testing that is not hypothesis driven (eg, microarray, whole exome sequencing). These ASD groups cannot be easily clinically defined because patients with a given variant have variable somatic abnormalities (dysmorphism and birth defects). In this article, we review common diagnoses from the above categories and suggest a testing strategy for patients, guided by determining whether the individual has essential or complex ASD; patients in the latter group have multiple morphologic anomalies on physical examination. Finally, we recommend that the syndromic versus nonsyndromic designation ultimately be replaced by classification of ASD according to its genetic etiology, which will inform about the associated spectrum and penetrance of neurobehavioral and somatic manifestations.
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Affiliation(s)
- Bridget A. Fernandez
- Disciplines of Genetics and Medicine, Faculty of Medicine, Memorial University of Newfoundland, St John's, NL Canada
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19
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Koemans TS, Kleefstra T, Chubak MC, Stone MH, Reijnders MRF, de Munnik S, Willemsen MH, Fenckova M, Stumpel CTRM, Bok LA, Sifuentes Saenz M, Byerly KA, Baughn LB, Stegmann APA, Pfundt R, Zhou H, van Bokhoven H, Schenck A, Kramer JM. Functional convergence of histone methyltransferases EHMT1 and KMT2C involved in intellectual disability and autism spectrum disorder. PLoS Genet 2017; 13:e1006864. [PMID: 29069077 PMCID: PMC5656305 DOI: 10.1371/journal.pgen.1006864] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 06/10/2017] [Indexed: 11/18/2022] Open
Abstract
Kleefstra syndrome, caused by haploinsufficiency of euchromatin histone methyltransferase 1 (EHMT1), is characterized by intellectual disability (ID), autism spectrum disorder (ASD), characteristic facial dysmorphisms, and other variable clinical features. In addition to EHMT1 mutations, de novo variants were reported in four additional genes (MBD5, SMARCB1, NR1I3, and KMT2C), in single individuals with clinical characteristics overlapping Kleefstra syndrome. Here, we present a novel cohort of five patients with de novo loss of function mutations affecting the histone methyltransferase KMT2C. Our clinical data delineates the KMT2C phenotypic spectrum and reinforces the phenotypic overlap with Kleefstra syndrome and other related ID disorders. To elucidate the common molecular basis of the neuropathology associated with mutations in KMT2C and EHMT1, we characterized the role of the Drosophila KMT2C ortholog, trithorax related (trr), in the nervous system. Similar to the Drosophila EHMT1 ortholog, G9a, trr is required in the mushroom body for short term memory. Trr ChIP-seq identified 3371 binding sites, mainly in the promoter of genes involved in neuronal processes. Transcriptional profiling of pan-neuronal trr knockdown and G9a null mutant fly heads identified 613 and 1123 misregulated genes, respectively. These gene sets show a significant overlap and are associated with nearly identical gene ontology enrichments. The majority of the observed biological convergence is derived from predicted indirect target genes. However, trr and G9a also have common direct targets, including the Drosophila ortholog of Arc (Arc1), a key regulator of synaptic plasticity. Our data highlight the clinical and molecular convergence between the KMT2 and EHMT protein families, which may contribute to a molecular network underlying a larger group of ID/ASD-related disorders. Neurodevelopmental disorders (NDDs) like intellectual disability (ID) and autism spectrum disorder (ASD) present an enormous challenge to affected individuals, their families, and society. Understanding the mechanisms underlying NDDs may lead to the development of targeted therapeutics, but this is complicated by the great clinical and genetic heterogeneity seen in patients. Mutations in hundreds of genes have been implicated in NDDs, giving rise to diverse clinical presentations. However, evidence suggests that many of these genes lie in common biological pathways, and mutations in genes that are involved in similar biological functions give rise to more similar clinical phenotypes. Here, we define a novel ID disorder with comorbid ASD (ID/ASD) caused by mutations in KMT2C. This disorder is defined by clinical features that overlap with a group of other disorders, including Kleefstra syndrome, which is caused by EHMT1 mutations. In the fruit fly, we show that the KMT2 and EHMT protein families regulate a highly converging set of biological processes. Both EHMT1 and KMT2C encode histone methyltransferases, which regulate gene transcription by modifying chromatin structure. Further understanding of the common gene regulatory networks associated with this group of ID- and ASD-related disorders may lead to the identification of novel therapeutic targets.
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Affiliation(s)
- Tom S. Koemans
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Melissa C. Chubak
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
| | - Max H. Stone
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
- Division of Genetics and Development, Children’s Health Research Institute, London, Ontario, Canada
| | - Margot R. F. Reijnders
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Sonja de Munnik
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Marjolein H. Willemsen
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Michaela Fenckova
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Connie T. R. M. Stumpel
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, the Netherlands
| | - Levinus A. Bok
- Department of Pediatrics, Máxima Medical Centre, Veldhoven, The Netherlands
| | | | - Kyna A. Byerly
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Linda B. Baughn
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Alexander P. A. Stegmann
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, the Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Huiqing Zhou
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Nijmegen, The Netherlands
- Department of Molecular Developmental Biology, Radboud University, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Annette Schenck
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
- * E-mail: (AS); (JMK)
| | - Jamie M. Kramer
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
- Division of Genetics and Development, Children’s Health Research Institute, London, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- * E-mail: (AS); (JMK)
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Diagnostic exome sequencing identifies a heterozygous MBD5 frameshift mutation in a family with intellectual disability and epilepsy. Eur J Med Genet 2017; 60:559-564. [PMID: 28807762 DOI: 10.1016/j.ejmg.2017.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 11/23/2022]
Abstract
Methyl-CpG-binding domain 5 (MBD5)-associated neurodevelopmental disorder caused by 2q23.1 or MBD5-specific mutation has been recently identified as a genetic disorder associated with autism spectrum disorders. Phenotypic features of 2q23.1 deletion or disruption of MBD5 gene include severe intellectual disability, seizure, significant speech impairment, sleep disturbance, and autistic-like behavioural problems. Here we report a 7-year-old girl with intellectual disability and epilepsy without previous clinical diagnosis. Diagnostic exome sequencing identified a novel frameshift mutation c.254_255delGA (p.Arg85Asnfs*6) in the MBD5 gene of the proband and her father. The proband's father with normal intelligence showed subclinical manifestations observed in subsequent investigations. Clinical manifestations, disease course, and molecular findings of the involvement of MBD5 gene in this family suggest an unusual MBD5-related neurodevelopmental disorder. Moreover, this report demonstrates the critical role of next-generation sequencing technique in characterizing such a rare disorder with variable or no clinical manifestation and providing opportunity to develop effective preventive measures such as pre-implantation genetic diagnosis.
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Copy Number Variations in Candidate Genes and Intergenic Regions Affect Body Mass Index and Abdominal Obesity in Mexican Children. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2432957. [PMID: 28428959 PMCID: PMC5385910 DOI: 10.1155/2017/2432957] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 01/26/2017] [Accepted: 02/06/2017] [Indexed: 01/11/2023]
Abstract
Introduction. Increase in body weight is a gradual process that usually begins in childhood and in adolescence as a result of multiple interactions among environmental and genetic factors. This study aimed to analyze the relationship between copy number variants (CNVs) in five genes and four intergenic regions with obesity in Mexican children. Methods. We studied 1423 children aged 6–12 years. Anthropometric measurements and blood levels of biochemical parameters were obtained. Identification of CNVs was performed by real-time PCR. The effect of CNVs on obesity or body composition was assessed using regression models adjusted for age, gender, and family history of obesity. Results. Gains in copy numbers of LEPR and NEGR1 were associated with decreased body mass index (BMI), waist circumference (WC), and risk of abdominal obesity, whereas gain in ARHGEF4 and CPXCR1 and the intergenic regions 12q15c, 15q21.1a, and 22q11.21d and losses in INS were associated with increased BMI and WC. Conclusion. Our results indicate a possible contribution of CNVs in LEPR, NEGR1, ARHGEF4, and CPXCR1 and the intergenic regions 12q15c, 15q21.1a, and 22q11.21d to the development of obesity, particularly abdominal obesity in Mexican children.
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Abstract
Purpose of Review Pitt Hopkins syndrome (PTHS) is a rare neurodevelopmental disorder that results from mutations of the clinically pleiotropic Transcription Factor 4 (TCF4) gene. Mutations in the genomic locus of TCF4 on chromosome 18 have been linked to multiple disorders including 18q syndrome, schizophrenia, Fuch's corneal dystrophy, and sclerosing cholangitis. For PTHS, TCF4 mutation or deletion leads to the production of a dominant negative TCF4 protein and/or haploinsufficiency that results in abnormal brain development. The biology of TCF4 has been studied for several years in regards to its role in immune cell differentiation, although its role in neurodevelopment and the mechanisms resulting in the severe symptoms of PTHS are not well studied. Recent Findings Here, we summarize the current understanding of PTHS and recent findings that have begun to describe the biological implications of TCF4 deficiency during brain development and into adulthood. In particular, we focus on recent work that has looked at the role of TCF4 biology within the context of PTHS and highlight the potential for identification of therapeutic targets for PTHS. Summary PTHS research continues to uncover mutations in TCF4 that underlie the genetic cause of this rare disease, and emerging evidence for molecular mechanisms that TCF4 regulates in brain development and neuronal function is contributing to a more complete picture of how pathology arises from this genetic basis, with important implications for the potential of future clinical care.
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Garay PM, Wallner MA, Iwase S. Yin-yang actions of histone methylation regulatory complexes in the brain. Epigenomics 2016; 8:1689-1708. [PMID: 27855486 PMCID: PMC5289040 DOI: 10.2217/epi-2016-0090] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/05/2016] [Indexed: 02/07/2023] Open
Abstract
Dysregulation of histone methylation has emerged as a major driver of neurodevelopmental disorders including intellectual disabilities and autism spectrum disorders. Histone methyl writer and eraser enzymes generally act within multisubunit complexes rather than in isolation. However, it remains largely elusive how such complexes cooperate to achieve the precise spatiotemporal gene expression in the developing brain. Histone H3K4 methylation (H3K4me) is a chromatin signature associated with active gene-regulatory elements. We review a body of literature that supports a model in which the RAI1-containing H3K4me writer complex counterbalances the LSD1-containing H3K4me eraser complex to ensure normal brain development. This model predicts H3K4me as the nexus of previously unrelated neurodevelopmental disorders.
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Affiliation(s)
- Patricia Marie Garay
- Neuroscience Graduate Program, The University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | | | - Shigeki Iwase
- Neuroscience Graduate Program, The University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Human Genetics, The University of Michigan, Ann Arbor, MI 48109, USA
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Clinical and Molecular Aspects of MBD5-Associated Neurodevelopmental Disorder (MAND). Eur J Hum Genet 2016; 24:1235-43. [PMID: 27222293 DOI: 10.1038/ejhg.2016.35] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 03/03/2016] [Accepted: 03/08/2016] [Indexed: 11/08/2022] Open
Abstract
MBD5-associated neurodevelopmental disorder (MAND) is an umbrella term that describes a group of disorders, 2q23.1 deletion syndrome, 2q23.1 duplication syndrome, and MBD5 variants, that affect the function of methyl-binding domain 5 (MBD5) and share a common set of neurodevelopmental, cognitive, and behavioral impairments. This review provides a comprehensive clinical and molecular synopsis of 2q23.1 deletion syndrome. Approaches to diagnosis, genetic counseling, and up-to-date management are summarized, followed by a discussion of the molecular and functional role of MBD5. Finally, we also include a brief summary of MBD5 variants that affect function of MBD5 and 2q23.1 duplication syndrome.
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Disruption of POGZ Is Associated with Intellectual Disability and Autism Spectrum Disorders. Am J Hum Genet 2016; 98:541-552. [PMID: 26942287 DOI: 10.1016/j.ajhg.2016.02.004] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/05/2016] [Indexed: 12/24/2022] Open
Abstract
Intellectual disability (ID) and autism spectrum disorders (ASD) are genetically heterogeneous, and a significant number of genes have been associated with both conditions. A few mutations in POGZ have been reported in recent exome studies; however, these studies do not provide detailed clinical information. We collected the clinical and molecular data of 25 individuals with disruptive mutations in POGZ by diagnostic whole-exome, whole-genome, or targeted sequencing of 5,223 individuals with neurodevelopmental disorders (ID primarily) or by targeted resequencing of this locus in 12,041 individuals with ASD and/or ID. The rarity of disruptive mutations among unaffected individuals (2/49,401) highlights the significance (p = 4.19 × 10(-13); odds ratio = 35.8) and penetrance (65.9%) of this genetic subtype with respect to ASD and ID. By studying the entire cohort, we defined common phenotypic features of POGZ individuals, including variable levels of developmental delay (DD) and more severe speech and language delay in comparison to the severity of motor delay and coordination issues. We also identified significant associations with vision problems, microcephaly, hyperactivity, a tendency to obesity, and feeding difficulties. Some features might be explained by the high expression of POGZ, particularly in the cerebellum and pituitary, early in fetal brain development. We conducted parallel studies in Drosophila by inducing conditional knockdown of the POGZ ortholog row, further confirming that dosage of POGZ, specifically in neurons, is essential for normal learning in a habituation paradigm. Combined, the data underscore the pathogenicity of loss-of-function mutations in POGZ and define a POGZ-related phenotype enriched in specific features.
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Cesaretti C, Spaccini L, Righini A, Parazzini C, Conte G, Crosti F, Redaelli S, Bulfamante G, Avagliano L, Rustico M. Prenatal detection of 5q14.3 duplication including MEF2C and brain phenotype. Am J Med Genet A 2016; 170A:1352-7. [PMID: 26864752 DOI: 10.1002/ajmg.a.37594] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 01/25/2016] [Indexed: 11/11/2022]
Abstract
The 5q14.3 duplication is a rare condition comprising speech and developmental delay, microcephaly, and mild ventriculomegaly. The region 5q14.3 contains several genes but the predominant role for the onset of the neurodevelopmental phenotype has been attributed to MEF2C. We describe the prenatal identification of 5q14.3 duplication, including MEF2C, in a monochorionic twin pregnancy with corpus callosum anomalies, confirmed by autopsy. To the best of our knowledge, this cerebral finding has been observed for the first time in 5q14.3 duplication patients, possibly widening the neurological picture of this scarcely known syndrome. A pathogenetic role of MEF2C overexpression in brain development may be assumed, but further studies are needed.
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Affiliation(s)
- Claudia Cesaretti
- Medical Genetics Unit, Fondazione I.R.C.C.S. Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Luigina Spaccini
- Fetal Therapy Unit, Department of Obstetrics and Gynaecology, Children's Hospital V. Buzzi, Milan, Italy
| | - Andrea Righini
- Department of Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy
| | - Cecilia Parazzini
- Department of Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy
| | - Giorgio Conte
- Department of Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy.,Department of Health Sciences, Specialization School of Radiology, University of Milan, Milan, Italy
| | - Francesca Crosti
- Medical Genetics Lab, Pathology Unit, San Gerardo Hospital, Monza, Italy
| | - Serena Redaelli
- Department of Surgery and Traslational Medicine, University of Milano-Bicocca, Monza, Italy
| | - Gaetano Bulfamante
- Department of Health Sciences, San Paolo Hospital Medical School, University of Milan, Milan, Italy
| | - Laura Avagliano
- Department of Health Sciences, San Paolo Hospital Medical School, University of Milan, Milan, Italy
| | - Mariangela Rustico
- Fetal Therapy Unit, Department of Obstetrics and Gynaecology, Children's Hospital V. Buzzi, Milan, Italy
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