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Baga M, Ivanovski I, Contrò G, Caraffi SG, Spagnoli C, Cesaroni CA, Neri A, Peluso F, Pollazzon M, Garavelli L, Fusco C. Novel Insights from Clinical Practice: Xia-Gibbs Syndrome with Pes Cavus, Conjunctival Melanosis, and Eye Asymmetry due to a de novo AHDC1 Gene Variant - A Case Report and a Brief Review of the Literature. Mol Syndromol 2024; 15:63-70. [PMID: 38357260 PMCID: PMC10862326 DOI: 10.1159/000530410] [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: 11/16/2021] [Accepted: 03/06/2023] [Indexed: 02/16/2024] Open
Abstract
Introduction Xia-Gibbs syndrome (OMIM 615829) is a rare developmental disorder, caused by heterozygous de novo variants in the AHDC1 gene. Hallmark features include global developmental delay, facial dysmorphisms, and behavioral problems. To date, more than 250 individuals have been diagnosed worldwide. Case Report We report a 13-year-old female who, in association with typical features of Xia-Gibbs syndrome, presented with macrocrania, pes cavus, and conjunctival melanosis. Whole-exome sequencing identified a de novo frameshift variant, which had not been reported in the literature before. Conclusion We summarized the main clinical and phenotypic features of patients described in the literature, and in addition, we discuss another feature found in our patient and observed in other cases described, eye asymmetry, which has never been highlighted, and suggest that it could be part of the typical clinical presentation of this condition.
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Affiliation(s)
- Margherita Baga
- Neuropsychiatric Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Ivan Ivanovski
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Gianluca Contrò
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | | | - Carlotta Spagnoli
- Neuropsychiatric Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | | | - Alberto Neri
- Ophthalmology Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Francesca Peluso
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Marzia Pollazzon
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Livia Garavelli
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Carlo Fusco
- Neuropsychiatric Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
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Chou WP, Chen YL, Hsiao RC, Lai YH, Yen CF. Bidirectional associations between hyperopia, myopia, astigmatism, and strabismus, and attention-deficit/hyperactivity disorder in children: a national population-based cohort study. REVISTA BRASILEIRA DE PSIQUIATRIA (SAO PAULO, BRAZIL : 1999) 2023; 45:397-404. [PMID: 37718319 PMCID: PMC10894630 DOI: 10.47626/1516-4446-2023-3156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 06/25/2023] [Indexed: 09/19/2023]
Abstract
OBJECTIVES The present study analyzed the reciprocal relationships between four common pediatric ophthalmic diseases (i.e., hyperopia, myopia, astigmatism, and strabismus) and attention-deficit/hyperactivity disorder (ADHD) in children. METHODS This study enrolled 86,028 children with ADHD and 1,798,673 children without ADHD in the Taiwan Maternal and Child Health Database who were born at any time from 2004 to 2017. Cox proportional hazards regression models were used to estimate the bidirectional relationships of the four ophthalmic diseases with ADHD in children after adjusting for age, sex, and gestational age at birth. Survival curves for time-to-event variables were estimated using the Kaplan-Meier method, and the log-rank test was used to compare the curves. RESULTS The results indicated that ADHD significantly predicted the occurrence of hyperopia, myopia, astigmatism, and strabismus. Furthermore, hyperopia, myopia, astigmatism, and strabismus significantly predicted the occurrence of ADHD. The time between enrollment and ADHD diagnosis was shorter for patients with ophthalmic diseases than for the control group, and the time between enrollment and ophthalmic disease diagnosis was also shorter for ADHD patients than for the control group. Sex differences were found in the associations between ADHD and ophthalmic diseases. CONCLUSION Clinicians should monitor children with ADHD for hyperopia, myopia, astigmatism, and strabismus to ensure appropriate treatment, and vice versa.
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Affiliation(s)
- Wei-Po Chou
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Psychiatry, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Lung Chen
- Department of Psychology, Asia University, Taichung, Taiwan
- Department of Healthcare Administration, Asia University, Taichung, Taiwan
| | - Ray C. Hsiao
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
- Department of Psychiatry, Seattle Children’s, Seattle, WA, USA
| | - Yu-Hung Lai
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Ophthalmology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Cheng-Fang Yen
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Psychiatry, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- College of Professional Studies, National Pingtung University of Science and Technology, Pingtung, Taiwan
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3
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Romano F, Falco M, Cappuccio G, Brunetti-Pierri N, Lonardo F, Torella A, Digilio MC, Dentici ML, Alfieri P, Agolini E, Novelli A, Garavelli L, Accogli A, Striano P, Scarano G, Nigro V, Scala M, Capra V. Genotype-phenotype spectrum and correlations in Xia-Gibbs syndrome: Report of five novel cases and literature review. Birth Defects Res 2022; 114:759-767. [PMID: 35716097 PMCID: PMC9545659 DOI: 10.1002/bdr2.2058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/03/2022] [Accepted: 05/08/2022] [Indexed: 11/06/2022]
Abstract
Background Xia‐Gibbs syndrome (XGS) is a rare neurodevelopmental disorder caused by pathogenic variants in the AT‐hook DNA‐binding motif‐containing 1 gene (AHDC1), encoding a protein with a crucial role in transcription and epigenetic regulation, axonogenesis, brain function, and neurodevelopment. AHDC1 variants possibly act through a dominant‐negative mechanism and may interfere with DNA repair processes, leading to genome instability and impaired DNA translesion repair. Variants affecting residues closer to the N‐terminal are thought to determine a milder phenotype with better cognitive performances. However, clean‐cut genotype–phenotype correlations are still lacking. Cases In this study, we investigated five subjects with XGS in whom exome sequencing led to the identification of five novel de novo pathogenic variants in AHDC1. All variants were extremely rare and predicted to cause a loss of protein function. The phenotype of the reported patients included developmental delay, hypotonia, and distinctive facial dysmorphisms. Additionally, uncommon clinical features were observed, including congenital hypothyroidism and peculiar skeletal abnormalities. Conclusions In this study, we report uncommon XGS features associated with five novel truncating variants in AHDC, thus expanding the genotype and phenotypic spectrum of this complex condition. We also compared our cases to previously reported cases, discussing the current status of genotype–phenotype correlations in XGS.
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Affiliation(s)
- Ferruccio Romano
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | | | - Gerarda Cappuccio
- Department of Translational Medicine, Federico II University, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Nicola Brunetti-Pierri
- Department of Translational Medicine, Federico II University, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | | | - Annalaura Torella
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Maria Cristina Digilio
- Medical Genetics Unit, Medical Genetics and Rare Disease Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Maria Lisa Dentici
- Medical Genetics Unit, Medical Genetics and Rare Disease Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Paolo Alfieri
- Neuropsichiatric Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Emanuele Agolini
- Translational Cytogenomics Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Antonio Novelli
- Translational Cytogenomics Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Livia Garavelli
- Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Andrea Accogli
- Division of Medical Genetics, Department of Specialized Medicine, McGill University, Quebec, Canada.,Department of Human Genetics, McGill University, Quebec, Canada
| | -
- Telethon Foundation, Rome, Italy
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | | | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Marcello Scala
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy.,Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Valeria Capra
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
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4
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Lumaka A, Carstens N, Devriendt K, Krause A, Kulohoma B, Kumuthini J, Mubungu G, Mukisa J, Nel M, Olanrewaju TO, Lombard Z, Landouré G. Increasing African genomic data generation and sharing to resolve rare and undiagnosed diseases in Africa: a call-to-action by the H3Africa rare diseases working group. Orphanet J Rare Dis 2022; 17:230. [PMID: 35710439 PMCID: PMC9201791 DOI: 10.1186/s13023-022-02391-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/06/2022] [Indexed: 11/10/2022] Open
Abstract
The rich and diverse genomics of African populations is significantly underrepresented in reference and in disease-associated databases. This renders interpreting the Next Generation Sequencing (NGS) data and reaching a diagnostic more difficult in Africa and for the African diaspora. It increases chances for false positives with variants being misclassified as pathogenic due to their novelty or rarity. We can increase African genomic data by (1) making consent for sharing aggregate frequency data an essential component of research toolkit; (2) encouraging investigators with African data to share available data through public resources such as gnomAD, AVGD, ClinVar, DECIPHER and to use MatchMaker Exchange; (3) educating African research participants on the meaning and value of sharing aggregate frequency data; and (4) increasing funding to scale-up the production of African genomic data that will be more representative of the geographical and ethno-linguistic variation on the continent. The RDWG of H3Africa is hereby calling to action because this underrepresentation accentuates the health disparities. Applying the NGS to shorten the diagnostic odyssey or to guide therapeutic options for rare diseases will fully work for Africans only when public repositories include sufficient data from African subjects.
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Affiliation(s)
- Aimé Lumaka
- Department of Pediatrics, Faculty of Medicine, Centre for Human Genetics, University of Kinshasa, Kinshasa, Congo. .,Laboratoire de Génétique Humaine, GIGA-Research Institute, University of Liège, Bât. B34 +2, Sart Tilman, Avenue de l'Hôpital 13, 4000, Liège, Belgium.
| | - Nadia Carstens
- Division of Human Genetics, National Health Laboratory Service, and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Koenraad Devriendt
- Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - Amanda Krause
- Division of Human Genetics, National Health Laboratory Service, and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Benard Kulohoma
- Centre for Biotechnology and Bioinformatics, University of Nairobi, Nairobi, Kenya.,ADVANCE, IAVI, Nairobi, Kenya
| | - Judit Kumuthini
- South African National Bioinformatics Institute (SANBI), University of Western Cape (UWC), Robert Sobukwe Road Bellville, Cape Town, 7535, Republic of South Africa
| | - Gerrye Mubungu
- Department of Pediatrics, Faculty of Medicine, Centre for Human Genetics, University of Kinshasa, Kinshasa, Congo.,Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - John Mukisa
- Department of Immunology and Molecular Biology, Makerere University College of Health Sciences, Third Floor, Pathology & Microbiology building Upper Mulago Hill, P.O.Box 7072, Kampala, Uganda
| | - Melissa Nel
- Neurology Research Group, Neuroscience Institute, University of Cape Town, Cape Town, 7925, South Africa
| | - Timothy O Olanrewaju
- Division of Nephrology, Department of Medicine, University of Ilorin and University of Ilorin Teaching Hospital, Tanke Road, PMB 1515, Ilorin, Kwara State, Nigeria.,Julius Global Health, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Zané Lombard
- Division of Human Genetics, National Health Laboratory Service, and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Guida Landouré
- Faculté de Médecine Et d'Odontostomatologie, USTTB, Bamako, Mali.,Service de Neurologie, Centre Hospitalier Universitaire du Point G, Bamako, Mali
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5
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Khayat MM, Hu J, Jiang Y, Li H, Chander V, Dawood M, Hansen AW, Li S, Friedman J, Cross L, Bijlsma EK, Ruivenkamp CA, Sansbury FH, Innis JW, Omark O’Shea J, Meng Q, Rosenfeld JA, McWalter K, Wangler MF, Lupski JR, Posey JE, Murdock D, Gibbs RA. AHDC1 missense mutations in Xia-Gibbs syndrome. HGG ADVANCES 2021; 2:100049. [PMID: 34950897 PMCID: PMC8694554 DOI: 10.1016/j.xhgg.2021.100049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/04/2021] [Indexed: 12/19/2022] Open
Abstract
Xia-Gibbs syndrome (XGS; MIM: 615829) is a phenotypically heterogeneous neurodevelopmental disorder (NDD) caused by newly arising mutations in the AT-Hook DNA-Binding Motif-Containing 1 (AHDC1) gene that are predicted to lead to truncated AHDC1 protein synthesis. More than 270 individuals have been diagnosed with XGS worldwide. Despite the absence of an independent assay for AHDC1 protein function to corroborate potential functional consequences of rare variant genetic findings, there are also reports of individuals with XGS-like trait manifestations who have de novo missense AHDC1 mutations and who have been provided a molecular diagnosis of the disorder. To investigate a potential contribution of missense mutations to XGS, we mapped the missense mutations from 10 such individuals to the AHDC1 conserved protein domain structure and detailed the observed phenotypes. Five newly identified individuals were ascertained from a local XGS Registry, and an additional five were taken from external reports or databases, including one publication. Where clinical data were available, individuals with missense mutations all displayed phenotypes consistent with those observed in individuals with AHDC1 truncating mutations, including delayed motor milestones, intellectual disability (ID), hypotonia, and speech delay. A subset of the 10 reported missense mutations cluster in two regions of the AHDC1 protein with known conserved domains, likely representing functional motifs. Variants outside the clustered regions score lower for computational prediction of their likely damaging effects. Overall, de novo missense variants in AHDC1 are likely diagnostic of XGS when in silico analysis of their position relative to conserved regions is considered together with disease trait manifestations.
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Affiliation(s)
- Michael M. Khayat
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jianhong Hu
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Yunyun Jiang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - He Li
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Varuna Chander
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Moez Dawood
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Adam W. Hansen
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Shoudong Li
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Jennifer Friedman
- UCSD Departments of Neuroscience and Pediatrics, Rady Children’s Hospital Division of Neurology, Rady Children’s Institute for Genomic Medicine, San Diego, CA, USA
| | - Laura Cross
- Department of Pediatrics and Genetics, Children’s Mercy Hospitals, Kansas City, MO, USA
| | - Emilia K. Bijlsma
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Francis H. Sansbury
- All Wales Medical Genomics Service, NHS Wales Cardiff and Vale University Health Board, Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
| | - Jeffrey W. Innis
- Departments of Human Genetics, Pediatrics, and Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Qingchang Meng
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | | | - Michael F. Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Neurological Research Institute, Houston, TX, USA
| | - James R. Lupski
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Hospital, Houston, TX, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Jennifer E. Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - David Murdock
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Richard A. Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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6
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Focusing on Autism Spectrum Disorder in Xia-Gibbs Syndrome: Description of a Female with High Functioning Autism and Literature Review. CHILDREN-BASEL 2021; 8:children8060450. [PMID: 34073322 PMCID: PMC8227570 DOI: 10.3390/children8060450] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/17/2021] [Accepted: 05/20/2021] [Indexed: 12/28/2022]
Abstract
Background: Xia–Gibbs syndrome (XGS) is a rare disorder caused by de novo mutations in the AT-Hook DNA binding motif Containing 1 (AHDC1) gene, which is characterised by a wide spectrum of clinical manifestations, including global developmental delay, intellectual disability, structural abnormalities of the brain, global hypotonia, feeding problems, sleep difficulties and apnoea, facial dysmorphisms, and short stature. Methods: Here, we report on a girl patient who shows a peculiar cognitive and behavioural profile including high-functioning autism spectrum disorder (ASD) without intellectual disability and provide information on her developmental trajectory with the aim of expanding knowledge of the XGS clinical spectrum. On the basis of the current clinical case and the literature review, we also attempt to deepen understanding of behavioural and psychiatric manifestations associated with XGS. Results: In addition to the patient we described, a considerable rate of individuals with XGS display autistic symptoms or have been diagnosed with an autistic spectrum disorder. Moreover, the analysis of the few psychopathological profiles of patients with XGS described in the literature shows a frequent presence of aggressive and self-injurious behaviours that could be either an expression of autistic functioning or an additional symptom of the ASD evolution. A careful investigation of the abovementioned symptoms is therefore required, since they could represent a “red flag” for ASD.
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7
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Khayat MM, Li H, Chander V, Hu J, Hansen AW, Li S, Traynelis J, Shen H, Weissenberger G, Stossi F, Johnson HL, Lupski JR, Posey JE, Sabo A, Meng Q, Murdock DR, Wangler M, Gibbs RA. Phenotypic and protein localization heterogeneity associated with AHDC1 pathogenic protein-truncating alleles in Xia-Gibbs syndrome. Hum Mutat 2021; 42:577-591. [PMID: 33644933 PMCID: PMC8115934 DOI: 10.1002/humu.24190] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 02/01/2021] [Accepted: 02/14/2021] [Indexed: 12/12/2022]
Abstract
Xia-Gibbs syndrome (XGS) is a rare Mendelian disease typically caused by de novo stop-gain or frameshift mutations in the AT-hook DNA binding motif containing 1 (AHDC1) gene. Patients usually present in early infancy with hypotonia and developmental delay and later exhibit intellectual disability (ID). The overall presentation is variable, however, and the emerging clinical picture is still evolving. A detailed phenotypic analysis of 34 XGS individuals revealed five core phenotypes (delayed motor milestones, speech delay, low muscle tone, ID, and hypotonia) in more than 80% of individuals and an additional 12 features that occurred more variably. Seizures and scoliosis were more frequently associated with truncations that arise before the midpoint of the protein although the occurrence of most features could not be predicted by the mutation position. Transient expression of wild type and different patient truncated AHDC1 protein forms in human cell lines revealed abnormal patterns of nuclear localization including a diffuse distribution of a short truncated form and nucleolar aggregation in mid-protein truncated forms. Overall, both the occurrence of variable phenotypes and the different distribution of the expressed protein reflect the heterogeneity of this syndrome.
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Affiliation(s)
- Michael M. Khayat
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
| | - He Li
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
| | - Varuna Chander
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
| | - Jianhong Hu
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
| | - Adam W. Hansen
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
| | - Shoudong Li
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
| | - Josh Traynelis
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
| | - Hua Shen
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
| | | | - Fabio Stossi
- Integrated Microscopy Core, Advanced Technology Cores, Dan
L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas,
USA
- Department of Molecular and Cellular Biology, Baylor
College of Medicine, Houston, Texas, USA
| | - Hannah L. Johnson
- Integrated Microscopy Core, Advanced Technology Cores, Dan
L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas,
USA
| | - James R. Lupski
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine,
Houston, Texas, USA
| | - Jennifer E. Posey
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
| | - Aniko Sabo
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
| | - Qingchang Meng
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
| | - David R. Murdock
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
| | - Michael Wangler
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
| | - Richard A. Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine,
Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College
of Medicine, Houston, Texas, USA
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