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León NY, Harley VR. ATR-X syndrome: genetics, clinical spectrum, and management. Hum Genet 2021; 140:1625-1634. [PMID: 34524523 DOI: 10.1007/s00439-021-02361-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 08/30/2021] [Indexed: 12/13/2022]
Abstract
ATR-X, an acronym for alpha thalassemia and mental retardation X-linked, syndrome is a congenital condition predominantly affecting males, characterized by mild to severe intellectual disability, facial, skeletal, urogenital, and hematopoietic anomalies. Less common are heart defects, eye anomalies, renal abnormalities, and gastrointestinal dysfunction. ATR-X syndrome is caused by germline variants in the ATRX gene. Until recently, the diagnosis of the ATR-X syndrome had been guided by the classical clinical manifestations and confirmed by molecular techniques. However, our new systematic analysis shows that the only clinical sign shared by all affected individuals is intellectual disability, with the other manifestations varying even within the same family. More than 190 different germline ATRX mutations in some 200 patients have been analyzed. With improved and more frequent analysis by molecular technologies, more subtle deletions and insertions have been detected recently. Moreover, emerging technologies reveal non-classic phenotypes of ATR-X syndrome as well as the description of a new clinical feature, the development of osteosarcoma which suggests an increased cancer risk in ATR-X syndrome. This review will focus on the different types of inherited ATRX mutations and their relation to clinical features in the ATR-X syndrome. We will provide an update of the frequency of clinical manifestations, the affected organs, and the genotype-phenotype correlations. Finally, we propose a shift in the diagnosis of ATR-X patients, from a clinical diagnosis to a molecular-based approach. This may assist clinicians in patient management, risk assessment and genetic counseling.
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Affiliation(s)
- Nayla Y León
- Sex Development Laboratory, Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, 27-31 Wright Street, Melbourne, VIC, 3168, Australia.,Department of Molecular and Translational Science, Monash University, Melbourne, VIC, Australia
| | - Vincent R Harley
- Sex Development Laboratory, Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, 27-31 Wright Street, Melbourne, VIC, 3168, Australia. .,Department of Molecular and Translational Science, Monash University, Melbourne, VIC, Australia.
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Piché J, Van Vliet PP, Pucéat M, Andelfinger G. The expanding phenotypes of cohesinopathies: one ring to rule them all! Cell Cycle 2019; 18:2828-2848. [PMID: 31516082 PMCID: PMC6791706 DOI: 10.1080/15384101.2019.1658476] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/13/2019] [Accepted: 08/17/2019] [Indexed: 12/13/2022] Open
Abstract
Preservation and development of life depend on the adequate segregation of sister chromatids during mitosis and meiosis. This process is ensured by the cohesin multi-subunit complex. Mutations in this complex have been associated with an increasing number of diseases, termed cohesinopathies. The best characterized cohesinopathy is Cornelia de Lange syndrome (CdLS), in which intellectual and growth retardations are the main phenotypic manifestations. Despite some overlap, the clinical manifestations of cohesinopathies vary considerably. Novel roles of the cohesin complex have emerged during the past decades, suggesting that important cell cycle regulators exert important biological effects through non-cohesion-related functions and broadening the potential pathomechanisms involved in cohesinopathies. This review focuses on non-cohesion-related functions of the cohesin complex, gene dosage effect, epigenetic regulation and TGF-β in cohesinopathy context, especially in comparison to Chronic Atrial and Intestinal Dysrhythmia (CAID) syndrome, a very distinct cohesinopathy caused by a homozygous Shugoshin-1 (SGO1) mutation (K23E) and characterized by pacemaker failure in both heart (sick sinus syndrome followed by atrial flutter) and gut (chronic intestinal pseudo-obstruction) with no intellectual or growth delay. We discuss the possible impact of SGO1 alterations in human pathologies and the potential impact of the SGO1 K23E mutation in the sinus node and gut development and functions. We suggest that the human phenotypes observed in CdLS, CAID syndrome and other cohesinopathies can inform future studies into the less well-known non-cohesion-related functions of cohesin complex genes. Abbreviations: AD: Alzheimer Disease; AFF4: AF4/FMR2 Family Member 4; ANKRD11: Ankyrin Repeat Domain 11; APC: Anaphase Promoter Complex; ASD: Atrial Septal Defect; ATRX: ATRX Chromatin Remodeler; ATRX: Alpha Thalassemia X-linked intellectual disability syndrome; BIRC5: Baculoviral IAP Repeat Containing 5; BMP: Bone Morphogenetic Protein; BRD4: Bromodomain Containing 4; BUB1: BUB1 Mitotic Checkpoint Serine/Threonine Kinase; CAID: Chronic Atrial and Intestinal Dysrhythmia; CDK1: Cyclin Dependent Kinase 1; CdLS: Cornelia de Lange Syndrome; CHD: Congenital Heart Disease; CHOPS: Cognitive impairment, coarse facies, Heart defects, Obesity, Pulmonary involvement, Short stature, and skeletal dysplasia; CIPO: Chronic Intestinal Pseudo-Obstruction; c-kit: KIT Proto-Oncogene Receptor Tyrosine Kinase; CoATs: Cohesin Acetyltransferases; CTCF: CCCTC-Binding Factor; DDX11: DEAD/H-Box Helicase 11; ERG: Transcriptional Regulator ERG; ESCO2: Establishment of Sister Chromatid Cohesion N-Acetyltransferase 2; GJC1: Gap Junction Protein Gamma 1; H2A: Histone H2A; H3K4: Histone H3 Lysine 4; H3K9: Histone H3 Lysine 9; HCN4: Hyperpolarization Activated Cyclic Nucleotide Gated Potassium and Sodium Channel 4;p HDAC8: Histone deacetylases 8; HP1: Heterochromatin Protein 1; ICC: Interstitial Cells of Cajal; ICC-MP: Myenteric Plexus Interstitial cells of Cajal; ICC-DMP: Deep Muscular Plexus Interstitial cells of Cajal; If: Pacemaker Funny Current; IP3: Inositol trisphosphate; JNK: C-Jun N-Terminal Kinase; LDS: Loeys-Dietz Syndrome; LOAD: Late-Onset Alzheimer Disease; MAPK: Mitogen-Activated Protein Kinase; MAU: MAU Sister Chromatid Cohesion Factor; MFS: Marfan Syndrome; NIPBL: NIPBL, Cohesin Loading Factor; OCT4: Octamer-Binding Protein 4; P38: P38 MAP Kinase; PDA: Patent Ductus Arteriosus; PDS5: PDS5 Cohesin Associated Factor; P-H3: Phospho Histone H3; PLK1: Polo Like Kinase 1; POPDC1: Popeye Domain Containing 1; POPDC2: Popeye Domain Containing 2; PP2A: Protein Phosphatase 2; RAD21: RAD21 Cohesin Complex Component; RBS: Roberts Syndrome; REC8: REC8 Meiotic Recombination Protein; RNAP2: RNA polymerase II; SAN: Sinoatrial node; SCN5A: Sodium Voltage-Gated Channel Alpha Subunit 5; SEC: Super Elongation Complex; SGO1: Shogoshin-1; SMAD: SMAD Family Member; SMC1A: Structural Maintenance of Chromosomes 1A; SMC3: Structural Maintenance of Chromosomes 3; SNV: Single Nucleotide Variant; SOX2: SRY-Box 2; SOX17: SRY-Box 17; SSS: Sick Sinus Syndrome; STAG2: Cohesin Subunit SA-2; TADs: Topology Associated Domains; TBX: T-box transcription factors; TGF-β: Transforming Growth Factor β; TGFBR: Transforming Growth Factor β receptor; TOF: Tetralogy of Fallot; TREK1: TREK-1 K(+) Channel Subunit; VSD: Ventricular Septal Defect; WABS: Warsaw Breakage Syndrome; WAPL: WAPL Cohesin Release Factor.
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Affiliation(s)
- Jessica Piché
- Cardiovascular Genetics, Department of Pediatrics, CHU Sainte-Justine, Montréal, QC, Canada
| | - Patrick Piet Van Vliet
- Cardiovascular Genetics, Department of Pediatrics, CHU Sainte-Justine, Montréal, QC, Canada
- LIA (International Associated Laboratory), CHU Sainte-Justine, Montréal, QC, Canada
- LIA (International Associated Laboratory), INSERM, Marseille, U1251-13885, France
| | - Michel Pucéat
- LIA (International Associated Laboratory), CHU Sainte-Justine, Montréal, QC, Canada
- LIA (International Associated Laboratory), INSERM, Marseille, U1251-13885, France
- INSERM U-1251, MMG,Aix-Marseille University, Marseille, 13885, France
| | - Gregor Andelfinger
- Cardiovascular Genetics, Department of Pediatrics, CHU Sainte-Justine, Montréal, QC, Canada
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Brosens E, Burns AJ, Brooks AS, Matera I, Borrego S, Ceccherini I, Tam PK, García-Barceló MM, Thapar N, Benninga MA, Hofstra RMW, Alves MM. Genetics of enteric neuropathies. Dev Biol 2016; 417:198-208. [PMID: 27426273 DOI: 10.1016/j.ydbio.2016.07.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 07/13/2016] [Accepted: 07/13/2016] [Indexed: 12/23/2022]
Abstract
Abnormal development or disturbed functioning of the enteric nervous system (ENS), the intrinsic innervation of the gastrointestinal tract, is associated with the development of neuropathic gastrointestinal motility disorders. Here, we review the underlying molecular basis of these disorders and hypothesize that many of them have a common defective biological mechanism. Genetic burden and environmental components affecting this common mechanism are ultimately responsible for disease severity and symptom heterogeneity. We believe that they act together as the fulcrum in a seesaw balanced with harmful and protective factors, and are responsible for a continuum of symptoms ranging from neuronal hyperplasia to absence of neurons.
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Affiliation(s)
- Erwin Brosens
- Department of Clinical Genetics, Erasmus University Medical Centre - Sophia Children's Hospital, Rotterdam, The Netherlands.
| | - Alan J Burns
- Department of Clinical Genetics, Erasmus University Medical Centre - Sophia Children's Hospital, Rotterdam, The Netherlands; Stem Cells and Regenerative Medicine, Birth Defects Research Centre, UCL Institute of Child Health, London, UK
| | - Alice S Brooks
- Department of Clinical Genetics, Erasmus University Medical Centre - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Ivana Matera
- UOC Medical Genetics, Istituto Giannina Gaslini, Genova, Italy
| | - Salud Borrego
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville (IBIS), Seville, Spain; Centre for Biomedical Network Research on Rare Diseases (CIBERER), Seville, Spain
| | | | - Paul K Tam
- Division of Paediatric Surgery, Department of Surgery, Li Ka Shing Faculty of Medicine of the University of Hong Kong, Hong Kong, China
| | - Maria-Mercè García-Barceló
- State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; Centre for Reproduction, Development, and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Nikhil Thapar
- Stem Cells and Regenerative Medicine, Birth Defects Research Centre, UCL Institute of Child Health, London, UK
| | - Marc A Benninga
- Pediatric Gastroenterology, Emma Children's Hospital/Academic Medical Center, Amsterdam, The Netherlands
| | - Robert M W Hofstra
- Department of Clinical Genetics, Erasmus University Medical Centre - Sophia Children's Hospital, Rotterdam, The Netherlands; Stem Cells and Regenerative Medicine, Birth Defects Research Centre, UCL Institute of Child Health, London, UK
| | - Maria M Alves
- Department of Clinical Genetics, Erasmus University Medical Centre - Sophia Children's Hospital, Rotterdam, The Netherlands
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Horesh N, Pery R, Amiel I, Shwaartz C, Speter C, Guranda L, Gutman M, Hoffman A. Volvulus and bowel obstruction in ATR-X syndrome-clinical report and review of literature. Am J Med Genet A 2015; 167A:2777-9. [PMID: 26174613 DOI: 10.1002/ajmg.a.37252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 06/26/2015] [Indexed: 11/11/2022]
Abstract
Alpha thalassemia-mental retardation, X-linked (ATR-X) syndrome is a rare genetic disorder with a variety of clinical manifestations. Gastrointestinal symptoms described in this syndrome include difficulties in feeding, regurgitation and vomiting which may lead to aspiration pneumonia, abdominal pain, distention, and constipation. We present a 19-year-old male diagnosed with ATR-X syndrome, who suffered from recurrent colonic volvulus that ultimately led to bowel necrosis with severe septic shock requiring emergent surgical intervention. During 1 year, the patient was readmitted four times due to poor oral intake, dehydration and abdominal distention. Investigation revealed partial small bowel volvulus which resolved with non-operative treatment. Small and large bowel volvulus are uncommon and life-threatening gastrointestinal manifestations of ATR-X patients, which may contribute to the common phenomenon of prolonged food refusal in these patients.
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Affiliation(s)
- Nir Horesh
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
| | - Ron Pery
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
| | - Imri Amiel
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
| | - Chaya Shwaartz
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
| | - Chen Speter
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
| | - Larisa Guranda
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
| | - Mordechai Gutman
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
| | - Aviad Hoffman
- Department of Surgery and Transplantation, Chaim Sheba Medical Center (affiliated with the Faculty of medicine, University of Tel Aviv, Tel Aviv, Israel), Tel-Hashomer, Ramat Gan, Israel
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Nistal M, Paniagua R, González-Peramato P, Reyes-Múgica M. Perspectives in Pediatric Pathology, Chapter 6. Male Undermasculinization. Pediatr Dev Pathol 2015; 18:279-96. [PMID: 25105706 DOI: 10.2350/14-04-1465-pb.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Normal male development requires three conditions: (1) adequate differentiation of the fetal testis; (2) synthesis and secretion of testicular hormones; and (3) effective action of these hormones on target organs. This requires the combined action of the inhibitory anti-müllerian hormone (AMH, secreted by Sertoli cells) to block the development of the uterus and fallopian tubes from the müllerian duct, together with the trophic stimulus of testosterone (a Leydig cell product), which leads to virilization of the wolffian ducts. Additionally, the development of external genitalia depends on the conversion of testosterone to dihydrotestosterone by the enzyme 5-α-reductase. Failure of any of these mechanisms leads to deficient virilization or the so-called "male pseudohermaphroditism" syndromes.
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Affiliation(s)
- Manuel Nistal
- 1 Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo #2, Madrid 28029, Spain
| | - Ricardo Paniagua
- 2 Department of Cell Biology, Universidad de Alcala, Madrid, Spain
| | - Pilar González-Peramato
- 1 Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo #2, Madrid 28029, Spain
| | - Miguel Reyes-Múgica
- 3 Department of Pathology, Children's Hospital of Pittsburgh of UPMC, One Children's Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
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Watanabe T, Arai K, Takahashi M, Ohno M, Sato K, Fuchimoto Y, Wada T, Ida S, Kawahara H, Kanamori Y. Esophago-gastric motility and nutritional management in a child with ATR-X syndrome. Pediatr Int 2014; 56:e48-51. [PMID: 25252072 DOI: 10.1111/ped.12402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 03/20/2014] [Accepted: 03/27/2014] [Indexed: 11/30/2022]
Abstract
X-linked alpha thalassemia mental retardation (ATR-X) syndrome is an X-linked recessive disorder that often involves gastrointestinal symptoms. Aspiration pneumonia related to gastroesophageal reflux has been reported as the major cause of death, but gastrointestinal function has not been well investigated. The present report describes a child with ATR-X syndrome who suffered from periodical episodes of refractory vomiting. We investigated the function of upper alimentary tract and found that esophago-gastric dysmotility and severe gastric volvulus were the major causes of gastrointestinal symptoms. This child was surgically treated with anterior gastropexy and jejunal alimentation through gastrostomy, and the symptoms were relieved with good weight gain. This report may provide insight into the gastrointestinal function and nutritional management in children with ATR-X syndrome.
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Affiliation(s)
- Toshihiko Watanabe
- Department of Surgical Subspecialties, Division of Surgery, National Center for Child Health and Development, Tokyo, Japan
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Peeters B, Benninga MA, Hennekam RC. Childhood constipation; an overview of genetic studies and associated syndromes. Best Pract Res Clin Gastroenterol 2011; 25:73-88. [PMID: 21382580 DOI: 10.1016/j.bpg.2010.12.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 12/03/2010] [Accepted: 12/13/2010] [Indexed: 01/31/2023]
Abstract
Constipation is a common problem in children but little is known about its exact pathophysiology. Environmental, behavioural but also genetic factors are thought to play a role in the aetiology of childhood constipation. We provide an overview of genetic studies performed in constipation. Until now, linkage studies, association studies and direct gene sequencing have failed to identify mutations in specific genes associated with constipation. We show that along with functional constipation, there are numerous clinical syndromes associated with childhood constipation. These syndromic forms of constipation appear to be the result of mutations in genes affecting all aspects of the normal physiology of human defecation. We stress that syndromic causes of childhood constipation should be considered in the evaluation of a constipated child.
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Affiliation(s)
- B Peeters
- Department of Paediatric Gastrointestinal Motility and Nutrition, Emma Children's Hospital, Academic Medical Centre, Amsterdam, The Netherlands.
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Dikow N, Junge C, Karch S, Hinderhofer K, Froster U, Moog U. Alpha-Thalassämie-Retardierungs-Syndrom. Monatsschr Kinderheilkd 2010. [DOI: 10.1007/s00112-010-2244-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Jezela-Stanek A, Fisher C, Szarras-Czapnik M, Olczak-Kowalczyk D, Gibbons RJ, Słowikowska-Hilczer J, Krajewska-Walasek M. X-linked alpha thalassaemia/mental retardation syndrome: a case with gonadal dysgenesis, caused by a novel mutation in ATRX gene. Clin Dysmorphol 2009; 18:168-171. [PMID: 19444090 DOI: 10.1097/mcd.0b013e32832a9ea5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Aleksandra Jezela-Stanek
- Departments of Medical Genetics Endocrinology Oral Pathology, The Children's Memorial Health Institute, Warsaw Department of Andrology and Reproductive Endocrinology, Institute of Endocrinology, Medical University of Lodz, Lodz, Poland MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK
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Kirienko NV, McEnerney JDK, Fay DS. Coordinated regulation of intestinal functions in C. elegans by LIN-35/Rb and SLR-2. PLoS Genet 2008; 4:e1000059. [PMID: 18437219 PMCID: PMC2312330 DOI: 10.1371/journal.pgen.1000059] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Accepted: 03/24/2008] [Indexed: 01/19/2023] Open
Abstract
LIN-35 is the sole C. elegans representative of the pocket protein family, which includes the mammalian Retinoblastoma protein pRb and its paralogs p107 and p130. In addition to having a well-established and central role in cell cycle regulation, pocket proteins have been increasingly implicated in the control of critical and diverse developmental and cellular processes. To gain a greater understanding of the roles of pocket proteins during development, we have characterized a synthetic genetic interaction between lin-35 and slr-2, which we show encodes a C2H2-type Zn-finger protein. Whereas animals harboring single mutations in lin-35 or slr-2 are viable and fertile, lin-35; slr-2 double mutants arrest uniformly in early larval development without obvious morphological defects. Using a combination of approaches including transcriptome profiling, mosaic analysis, starvation assays, and expression analysis, we demonstrate that both LIN-35 and SLR-2 act in the intestine to regulate the expression of many genes required for normal nutrient utilization. These findings represent a novel role for pRb family members in the maintenance of organ function. Our studies also shed light on the mechanistic basis of genetic redundancy among transcriptional regulators and suggest that synthetic interactions may result from the synergistic misregulation of one or more common targets.
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Affiliation(s)
- Natalia V. Kirienko
- Department of Molecular Biology, College of Agriculture, University of Wyoming, Laramie, Wyoming, United States of America
| | - John D. K. McEnerney
- Department of Molecular Biology, College of Agriculture, University of Wyoming, Laramie, Wyoming, United States of America
| | - David S. Fay
- Department of Molecular Biology, College of Agriculture, University of Wyoming, Laramie, Wyoming, United States of America
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Gibbons R. Alpha thalassaemia-mental retardation, X linked. Orphanet J Rare Dis 2006; 1:15. [PMID: 16722615 PMCID: PMC1464382 DOI: 10.1186/1750-1172-1-15] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 05/04/2006] [Indexed: 11/29/2022] Open
Abstract
X-linked alpha thalassaemia mental retardation (ATR-X) syndrome in males is associated with profound developmental delay, facial dysmorphism, genital abnormalities and alpha thalassaemia. Female carriers are usually physically and intellectually normal. So far, 168 patients have been reported. Language is usually very limited. Seizures occur in about one third of the cases. While many patients are affectionate with their caregivers, some exhibit autistic-like behaviour. Patients present with facial hypotonia and a characteristic mouth. Genital abnormalities are observed in 80% of children and range from undescended testes to ambiguous genitalia. Alpha-thalassaemia is not always present. This syndrome is X-linked recessive and results from mutations in the ATRX gene. This gene encodes the widely expressed ATRX protein. ATRX mutations cause diverse changes in the pattern of DNA methylation at heterochromatic loci but it is not yet known whether this is responsible for the clinical phenotype. The diagnosis can be established by detection of alpha thalassaemia, identification of ATRX gene mutations, ATRX protein studies and X-inactivation studies. Genetic counselling can be offered to families. Management is multidisciplinary: young children must be carefully monitored for gastro-oesophageal reflux as it may cause death. A number of individuals with ATR-X are fit and well in their 30s and 40s.
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Affiliation(s)
- Richard Gibbons
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Headington, OX3 9DS Oxford, UK.
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