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Vos N, Menke LA, Mooij CF, van den Akker ELT, Alders M, van Haelst MM. Severe early-onset overgrowth in a case of pseudohypoparathyroidism type 1b, caused by STX16 deletion. Am J Med Genet A 2023; 191:1476-1478. [PMID: 36807968 DOI: 10.1002/ajmg.a.63154] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/22/2023]
Affiliation(s)
- Niels Vos
- Department of Human Genetics, Amsterdam University Medical Center, University of Amsterdam, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | - Leonie A Menke
- Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | - Christiaan F Mooij
- Department of Pediatric Endocrinology, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Erica L T van den Akker
- Division of Endocrinology, Department of Pediatrics, Erasmus MC-Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Mariëlle Alders
- Department of Human Genetics, Amsterdam University Medical Center, University of Amsterdam, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | - Mieke M van Haelst
- Department of Human Genetics, Amsterdam University Medical Center, University of Amsterdam, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
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2
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Elli FM, Mantovani G. Pseudohypoparathyroidism, acrodysostosis, progressive osseous heteroplasia: different names for the same spectrum of diseases? Endocrine 2021; 72:611-618. [PMID: 33179219 PMCID: PMC8159830 DOI: 10.1007/s12020-020-02533-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/24/2020] [Indexed: 12/27/2022]
Abstract
Pseudohypoparathyroidism (PHP), the first known post-receptorial hormone resistance, derives from a partial deficiency of the α subunit of the stimulatory G protein (Gsα), a key component of the PTH/PTHrP signaling pathway. Since its first description, different studies unveiled, beside the molecular basis for PHP, the existence of different subtypes and of diseases in differential diagnosis associated with genetic alterations in other genes of the PTH/PTHrP pathway. The clinical and molecular overlap among PHP subtypes and with different but related disorders make both differential diagnosis and genetic counseling challenging. Recently, a proposal to group all these conditions under the novel term "inactivating PTH/PTHrP signaling disorders (iPPSD)" was promoted and, soon afterwards, the first international consensus statement on the diagnosis and management of these disorders has been published. This review will focus on the major and minor features characterizing PHP/iPPSDs as a group and on the specificities as well as the overlap associated with the most frequent subtypes.
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Affiliation(s)
- Francesca Marta Elli
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giovanna Mantovani
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
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Rhyu J, Bhat SP. Skeletal Complications With GNAS Mutation: An Unusual Case With Osteoma Cutis, Gout, and Synovial Chondromatosis in a Patient With Pseudopseudohypoparathyroidism. AACE Clin Case Rep 2021; 7:180-183. [PMID: 34095483 PMCID: PMC8165112 DOI: 10.1016/j.aace.2020.11.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/21/2020] [Accepted: 11/30/2020] [Indexed: 11/13/2022] Open
Abstract
Objective We present a patient with pseudopseudohypoparathyroidism (PPHP) who developed both gout and synovial chondromatosis, in addition to the classical Albright's hereditary osteodystrophy phenotype. Methods The patient's clinical course, laboratory data, and imaging are presented. Results The patient is a 40-year-old male with no pertinent family history who presented with findings of Albright's hereditary osteodystrophy, including short stature, obesity, rounded face, shortened fourth and fifth digits, and osteoma cutis (heterotopic subcutaneous ossification), which required surgical removal for pain relief. Genetic testing confirmed a GNAS mutation, and labs showed normal parathyroid hormone, calcium, and phosphorus levels, diagnostic of PPHP. The patient later developed gout and synovial chondromatosis, a rare benign process where the synovial membrane forms calcified loose bodies within the joint. Conclusion The patient case highlights the musculoskeletal complications of PPHP. Though PPHP has been rarely associated separately with gout or synovial chondromatosis, this is the first reported patient to have developed both conditions. This case raises the significance of multidisciplinary follow up for potential orthopedic complications. Moreover, the case underscores the importance of genetics and epigenetics in skeletal health, independent of calcium homeostasis in the blood.
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Affiliation(s)
- Jane Rhyu
- Address correspondence and reprint requests to Dr. Jane Rhyu, Division of Endocrinology, Diabetes, and Metabolism, Department of Internal Medicine, David Geffen School of Medicine at University of California Los Angeles Los Angeles, CA 90095.
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Tami L, Rherib C, Chefchaouni K, Knouni H, Barkat A. Ostéodystrophie héréditaire d'Albright: à propos d'une observation. Pan Afr Med J 2019; 34:190. [PMID: 32180864 PMCID: PMC7060915 DOI: 10.11604/pamj.2019.34.190.13398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 12/02/2019] [Indexed: 11/15/2022] Open
Abstract
L'ostéodystrophie héréditaire d'Albright est une pathologie rare, associée à des troubles du bilan phosphocalcique liés à une résistance périphérique à la parathormone. Il s'agit d'une affection héréditaire, transmise sur le mode autosomique dominant et qui résulte d'une anomalie du gène GNAS1. Elle associe un morphotype particulier, des calcifications sous cutanées et une résistance osseuse et rénale à la parathormone. Nous rapportons un nouveau cas d'ostéodystrophie héréditaire d'Albright chez un nourrisson de 9 mois, suivi pour hypocalcémie profonde depuis j10 de vie. A travers ce cas, nous rappelons les différents aspects de cette affection sur les plans clinique, biologique, génétique ainsi que thérapeutique.
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Affiliation(s)
- Laila Tami
- Service de Néonatologie, Centre National de Référence en Néonatologie et en Nutrition, Hôpital d'Enfants, Rabat, CHU Ibn-Sina, Maroc
| | - Chaima Rherib
- Service de Néonatologie, Centre National de Référence en Néonatologie et en Nutrition, Hôpital d'Enfants, Rabat, CHU Ibn-Sina, Maroc
| | - Kanza Chefchaouni
- Service de Néonatologie, Centre National de Référence en Néonatologie et en Nutrition, Hôpital d'Enfants, Rabat, CHU Ibn-Sina, Maroc
| | - Houria Knouni
- Service de Néonatologie, Centre National de Référence en Néonatologie et en Nutrition, Hôpital d'Enfants, Rabat, CHU Ibn-Sina, Maroc
| | - Amina Barkat
- Service de Néonatologie, Centre National de Référence en Néonatologie et en Nutrition, Hôpital d'Enfants, Rabat, CHU Ibn-Sina, Maroc
- Équipe de Recherche en Santé et Nutrition du Couple Mère-Enfant, Faculté de Médecine et de Pharmacie de Rabat, Université Mohammed V, Rabat, Maroc
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Martos-Moreno GÁ, Lecumberri B, Pérez de Nanclares G. Implicaciones en pediatría del primer consenso internacional para el diagnóstico y asistencia a pacientes con pseudohipoparatiroidismo y enfermedades relacionadas. An Pediatr (Barc) 2019; 90:125.e1-125.e12. [DOI: 10.1016/j.anpedi.2018.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 11/22/2018] [Indexed: 02/08/2023] Open
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Martos-Moreno GÁ, Lecumberri B, Pérez de Nanclares G. Implication in Paediatrics of the First International Consensus Statement for the Diagnosis and management of pseudohypoparathyroidism and related disorders. ANALES DE PEDIATRÍA (ENGLISH EDITION) 2019. [DOI: 10.1016/j.anpede.2019.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Mantovani G, Bastepe M, Monk D, de Sanctis L, Thiele S, Usardi A, Ahmed SF, Bufo R, Choplin T, De Filippo G, Devernois G, Eggermann T, Elli FM, Freson K, García Ramirez A, Germain-Lee EL, Groussin L, Hamdy N, Hanna P, Hiort O, Jüppner H, Kamenický P, Knight N, Kottler ML, Le Norcy E, Lecumberri B, Levine MA, Mäkitie O, Martin R, Martos-Moreno GÁ, Minagawa M, Murray P, Pereda A, Pignolo R, Rejnmark L, Rodado R, Rothenbuhler A, Saraff V, Shoemaker AH, Shore EM, Silve C, Turan S, Woods P, Zillikens MC, Perez de Nanclares G, Linglart A. Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement. Nat Rev Endocrinol 2018; 14:476-500. [PMID: 29959430 PMCID: PMC6541219 DOI: 10.1038/s41574-018-0042-0] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This Consensus Statement covers recommendations for the diagnosis and management of patients with pseudohypoparathyroidism (PHP) and related disorders, which comprise metabolic disorders characterized by physical findings that variably include short bones, short stature, a stocky build, early-onset obesity and ectopic ossifications, as well as endocrine defects that often include resistance to parathyroid hormone (PTH) and TSH. The presentation and severity of PHP and its related disorders vary between affected individuals with considerable clinical and molecular overlap between the different types. A specific diagnosis is often delayed owing to lack of recognition of the syndrome and associated features. The participants in this Consensus Statement agreed that the diagnosis of PHP should be based on major criteria, including resistance to PTH, ectopic ossifications, brachydactyly and early-onset obesity. The clinical and laboratory diagnosis should be confirmed by a molecular genetic analysis. Patients should be screened at diagnosis and during follow-up for specific features, such as PTH resistance, TSH resistance, growth hormone deficiency, hypogonadism, skeletal deformities, oral health, weight gain, glucose intolerance or type 2 diabetes mellitus, and hypertension, as well as subcutaneous and/or deeper ectopic ossifications and neurocognitive impairment. Overall, a coordinated and multidisciplinary approach from infancy through adulthood, including a transition programme, should help us to improve the care of patients affected by these disorders.
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Affiliation(s)
- Giovanna Mantovani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Murat Bastepe
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - David Monk
- Imprinting and Cancer Group, Cancer Epigenetic and Biology Program (PEBC), Institut d'Investigació Biomedica de Bellvitge (IDIBELL), Barcelona, Spain
| | - Luisa de Sanctis
- Pediatric Endocrinology Unit, Department of Public Health and Pediatric Sciences, University of Torino, Turin, Italy
| | - Susanne Thiele
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, University of Lübeck, Lübeck, Germany
| | - Alessia Usardi
- APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Platform of Expertise Paris-Sud for Rare Diseases and Filière OSCAR, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
- APHP, Endocrinology and diabetes for children, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
| | - S Faisal Ahmed
- Developmental Endocrinology Research Group, School of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow, UK
| | - Roberto Bufo
- IPOHA, Italian Progressive Osseous Heteroplasia Association, Cerignola, Foggia, Italy
| | - Timothée Choplin
- K20, French PHP and related disorders patient association, Jouars Pontchartrain, France
| | - Gianpaolo De Filippo
- APHP, Department of medicine for adolescents, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
| | - Guillemette Devernois
- K20, French PHP and related disorders patient association, Jouars Pontchartrain, France
| | - Thomas Eggermann
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Francesca M Elli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Kathleen Freson
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, Gasthuisberg, University of Leuven, Leuven, Belgium
| | - Aurora García Ramirez
- AEPHP, Spanish PHP and related disorders patient association, Huércal-Overa, Almería, Spain
| | - Emily L Germain-Lee
- Albright Center & Center for Rare Bone Disorders, Division of Pediatric Endocrinology & Diabetes, Connecticut Children's Medical Center, Farmington, CT, USA
- Department of Pediatrics, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Lionel Groussin
- APHP, Department of Endocrinology, Cochin Hospital (HUPC), Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Neveen Hamdy
- Department of Medicine, Division of Endocrinology and Centre for Bone Quality, Leiden University Medical Center, Leiden, Netherlands
| | - Patrick Hanna
- INSERM U1169, Bicêtre Paris Sud, Paris Sud - Paris Saclay University, Le Kremlin-Bicêtre, France
| | - Olaf Hiort
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, University of Lübeck, Lübeck, Germany
| | - Harald Jüppner
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Peter Kamenický
- APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Platform of Expertise Paris-Sud for Rare Diseases and Filière OSCAR, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
- APHP, Department of Endocrinology and Reproductive Diseases, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
- INSERM U1185, Paris Sud - Paris Saclay University, Le Kremlin-Bicêtre, France
| | - Nina Knight
- UK acrodysostosis patients' group, London, UK
| | - Marie-Laure Kottler
- Department of Genetics, Reference Centre for Rare Disorders of Calcium and Phosphate Metabolism, Caen University Hospital, Caen, France
- BIOTARGEN, UNICAEN, Normandie University, Caen, France
| | - Elvire Le Norcy
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
- APHP, Department of Odontology, Bretonneau Hospital (PNVS), Paris, France
| | - Beatriz Lecumberri
- Department of Endocrinology and Nutrition, La Paz University Hospital, Madrid, Spain
- Department of Medicine, Autonomous University of Madrid (UAM), Madrid, Spain
- Endocrine Diseases Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Michael A Levine
- Division of Endocrinology and Diabetes and Center for Bone Health, Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Outi Mäkitie
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Regina Martin
- Osteometabolic Disorders Unit, Hormone and Molecular Genetics Laboratory (LIM/42), Endocrinology Division, Hospital das Clínicas HCFMUSP, Faculty of Medicine, University of Sao Paulo, Sao Paulo, Brazil
| | - Gabriel Ángel Martos-Moreno
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, CIBERobn, ISCIII, Madrid, Spain
- Department of Pediatrics, Autonomous University of Madrid (UAM), Madrid, Spain
- Endocrine Diseases Research Group, Hospital La Princesa Institute for Health Research (IIS La Princesa), Madrid, Spain
| | | | - Philip Murray
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Arrate Pereda
- Molecular (Epi)Genetics Laboratory, BioAraba National Health Institute, Hospital Universitario Araba-Txagorritxu, Vitoria-Gasteiz, Alava, Spain
| | | | - Lars Rejnmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Rebecca Rodado
- AEPHP, Spanish PHP and related disorders patient association, Huércal-Overa, Almería, Spain
| | - Anya Rothenbuhler
- APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Platform of Expertise Paris-Sud for Rare Diseases and Filière OSCAR, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
- APHP, Endocrinology and diabetes for children, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
| | - Vrinda Saraff
- Department of Endocrinology and Diabetes, Birmingham Children's Hospital, Birmingham, UK
| | - Ashley H Shoemaker
- Pediatric Endocrinology and Diabetes, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Eileen M Shore
- Departments of Orthopaedic Surgery and Genetics, Center for Research in FOP and Related Disorders, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Caroline Silve
- APHP, Service de Biochimie et Génétique Moléculaires, Hôpital Cochin, Paris, France
| | - Serap Turan
- Department of Pediatrics, Division of Endocrinology and Diabetes, Marmara University, Istanbul, Turkey
| | | | - M Carola Zillikens
- Department of Internal Medicine, Bone Center Erasmus MC - University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Guiomar Perez de Nanclares
- Molecular (Epi)Genetics Laboratory, BioAraba National Health Institute, Hospital Universitario Araba-Txagorritxu, Vitoria-Gasteiz, Alava, Spain.
| | - Agnès Linglart
- APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Platform of Expertise Paris-Sud for Rare Diseases and Filière OSCAR, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France.
- APHP, Endocrinology and diabetes for children, Bicêtre Paris Sud Hospital (HUPS), Le Kremlin-Bicêtre, France.
- INSERM U1169, Bicêtre Paris Sud, Paris Sud - Paris Saclay University, Le Kremlin-Bicêtre, France.
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Winfeld MJ, Otero H. Radiographic assessment of congenital malformations of the upper extremity. Pediatr Radiol 2016; 46:1454-70. [PMID: 27306656 DOI: 10.1007/s00247-016-3647-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 04/17/2016] [Accepted: 05/17/2016] [Indexed: 02/07/2023]
Abstract
Congenital and developmental malformations of the upper extremity are uncommon and their diagnosis can challenge radiologists. Many complex classification systems exist, the latest of which accounts for the complex embryology and pathogenetic mechanisms that govern the formation of these anomalies. Using appropriate descriptors allows for more specific diagnosis and improved consultation with referring pediatricians and surgeons, helping to guide medical and surgical interventions and, if indicated, further investigation for associated abnormalities and underlying syndromes. We review the imaging characteristics of upper limb malformations to help pediatric radiologists better understand the classification and workup necessary in these cases.
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Affiliation(s)
- Matthew J Winfeld
- Department of Radiology, Musculoskeletal Division, Penn Medicine University City, Perelman School of Medicine at the University of Pennsylvania, 3737 Market St., 7th floor, Philadelphia, PA, 19104, USA.
| | - Hansel Otero
- Department of Radiology, Children's National Medical Center, Washington, DC, USA
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Ohta S, Wang B, Mansour SL, Schoenwolf GC. BMP regulates regional gene expression in the dorsal otocyst through canonical and non-canonical intracellular pathways. Development 2016; 143:2228-37. [PMID: 27151948 DOI: 10.1242/dev.137133] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 04/27/2016] [Indexed: 12/13/2022]
Abstract
The inner ear consists of two otocyst-derived, structurally and functionally distinct components: the dorsal vestibular and ventral auditory compartments. BMP signaling is required to form the vestibular compartment, but how it complements other required signaling molecules and acts intracellularly is unknown. Using spatially and temporally controlled delivery of signaling pathway regulators to developing chick otocysts, we show that BMP signaling regulates the expression of Dlx5 and Hmx3, both of which encode transcription factors essential for vestibular formation. However, although BMP regulates Dlx5 through the canonical SMAD pathway, surprisingly, it regulates Hmx3 through a non-canonical pathway involving both an increase in cAMP-dependent protein kinase A activity and the GLI3R to GLI3A ratio. Thus, both canonical and non-canonical BMP signaling establish the precise spatiotemporal expression of Dlx5 and Hmx3 during dorsal vestibular development. The identification of the non-canonical pathway suggests an intersection point between BMP and SHH signaling, which is required for ventral auditory development.
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Affiliation(s)
- Sho Ohta
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84132-3401, USA
| | - Baolin Wang
- Department of Cell and Developmental Biology and Genetic Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Suzanne L Mansour
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84132-3401, USA Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112-5330, USA
| | - Gary C Schoenwolf
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84132-3401, USA
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Hindley KE, Billson FM, Piripi S, Verbruggen AM, Havlicek M. Primary isolated osteoma cutis causing eyelid deformation and strabismus in a dog. Vet Ophthalmol 2015; 19:439-43. [PMID: 26398878 DOI: 10.1111/vop.12314] [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] [Indexed: 11/28/2022]
Abstract
Osteoma cutis describes bone formation in skin and is well documented in the medical literature, but veterinary reports are few. We report a single case of a juvenile samoyed that was referred for assessment of a superior eyelid anomaly. Exploratory surgery and histopathology revealed the presence of mature, lamellar bone within the superior eyelid. The histologic appearance was consistent with primary osteoma cutis. The presence of the ossification within the deep dermis of the eyelid was associated with an abnormal conformation causing trichiasis, keratitis and dorsal strabismus. Identification of the osseous lesion during surgery and its removal was curative with no recurrence of disease during the 32 month follow-up period.
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Affiliation(s)
- Kate E Hindley
- Department of Ophthalmology, Small Animal Specialist Hospital, North Ryde, NSW, Australia.
| | - F Mark Billson
- Department of Ophthalmology, Small Animal Specialist Hospital, North Ryde, NSW, Australia
| | - Susan Piripi
- Department of Pathology, University Veterinary Teaching Hospital, University of Sydney, Camden, NSW, Australia
| | | | - Martin Havlicek
- Department of Surgery, Small Animal Specialist Hospital, North Ryde, NSW, Australia
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Hugar D, Sajjanshetty S, Hugar S, Kadani M. Albright hereditary osteodystrophy: a case report. J Clin Diagn Res 2014; 8:ZD28-30. [PMID: 25478468 DOI: 10.7860/jcdr/2014/10913.5041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/12/2014] [Indexed: 12/12/2022]
Abstract
A dental practitioner with an eagle's eye can diagnose many hidden disease through careful examination of the oral cavity. One such hereditary metabolic disorder is Albright hereditary osteodystrophy (AHO). Characteristic presentations in an individual affected by AHO were short stature, obesity and brachydactyly especially of 4(th) and 5(th) digits, which are the phenotypic features of genetic mutation. Pseudohypoparathyroidism (PHP) is characterized by inability of the body to respond appropriately to parathormone, mainly characterized by hypocalcemia, increased serum parathormone concentration, insensitivity to the biological activity of parathormone and hyperphosphatemia. AHO when seen in association with resistance to parathormone (PTH), it is called PHP. Here is, a case report of 32-year-old male patient with AHO with distinctive physical characteristics and oral manifestations.
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Affiliation(s)
- Deepa Hugar
- Senior Lecturer, Department of Oral and Maxillofacial Pathology, H.K.E.S's S.Nijalingappa Institute of Dental Sciences & Research , Sedam Road, Gulbarga, Karnataka, India
| | - Sangameshwar Sajjanshetty
- Reader, Department of Pedodontics and Preventive Dentistry, H.K.E.S's S.Nijalingappa Institute of Dental Sciences & Research , Sedam Road, Gulbarga, Karnataka, India
| | - Santosh Hugar
- Reader, Department Conservative and Endodontics, Bharatiya Vidyapeeth Dental College and Hospital , Sangli, Maharastra, India
| | - Megha Kadani
- Post Graduate, Department of Oral and Maxillofacial Pathology, H.K.E.S's S.Nijalingappa Institute of Dental Sciences & Research , Sedam Road, Gulbarga, Karnataka, India
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Hasani-Ranjbar S, Jouyandeh Z, Amoli MM, Soltani A, Arzaghi SM. A patient with features of albright hereditory osteodystrophy and unusual neuropsychiatric findings without coding Gsalpha mutations. J Diabetes Metab Disord 2014; 13:56. [PMID: 24959527 PMCID: PMC4067066 DOI: 10.1186/2251-6581-13-56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 04/10/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND Pseudohypoparathyroidism(PHP) is a heterogeneous group of rare metabolic disorders characterized by hypocalcemia and hyperphosphatemia resulting from PTH resistance. Different forms of PHP have been reported based on biochemical and clinical manifestation and genetic findings. Most of these forms are caused by defects in GNAS, an imprinted gene locus with multiple subunits. We reported a 12- year- old girl with unusual clinical manifestations of Pseudopseudohypoparathyroidism(PPHP). METHODS After clinical and biochemical evaluations, the patients' genomic DNA was isolated from peripheral blood leukocytes using salting out method. The whole coding sequences of GNAS gene including 13 exons were amplified by PCR. Quantitative PCR reactions were performed too. FINDINGS We described a 12- year- old girl with Albright Hereditory osteodystrophy (AHO) phenotype, poor school performance, some abnormal movements, TSH resistance with normal serum calcium and phosphorus levels and normal Gsα bioactivity with no mutation in GNAS exons. Unusual neuropsychiatric findings in this patient were compatible with Asperger syndrome. CONCLUSIONS According to our findings this patient could not be categorized in any of PHP subgroups. Identifying of such individuals may be useful to discover different genetic patterns in pseudohypoparathyroidism and pseudopseudohypoparathyroidism. It is important to identify patients in whom PHP is caused by novel GNAS mutations, as careful investigations of these findings will likely further our knowledge of this complex and this unique disorder. In addition this case presented with unusual neuropsychiatric findings which has not been reported up to now.
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Affiliation(s)
- Shirin Hasani-Ranjbar
- Obesity & Eating Habits Research Center, Endocrinology and metabolism Cellular & Molecular Science Institute, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran ; Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran ; Endocrinology & Metabolism Research Institute, 5th Floor, Shariati Hospital, North Kargar Ave., Tehran 14114, Iran
| | - Zahra Jouyandeh
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahsa Mohammad Amoli
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Akbar Soltani
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Masoud Arzaghi
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
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13
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Agrawal L, Habib Z, Emanuele NV. Neurologic disorders of mineral metabolism and parathyroid disease. HANDBOOK OF CLINICAL NEUROLOGY 2014; 120:737-48. [PMID: 24365349 DOI: 10.1016/b978-0-7020-4087-0.00049-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Disorders of mineral metabolism may cause neurologic manifestations of the central and peripheral nervous systems. This is because plasma calcium stabilizes excitable membranes in the nerve and muscle tissue, magnesium is predominantly intracellular and is required for activation of many intracellular enzymes, and extracellular magnesium affects synaptic transmission. This chapter reviews abnormalities in electrolytes and minerals which can be associated with several neuromuscular symptoms including neuromuscular irritability, mental status changes, cardiac and smooth muscle changes, etc.
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Affiliation(s)
- Lily Agrawal
- Division of Endocrinology and Metabolism, Loyola University Medical Center, Maywood, IL, USA.
| | - Zeina Habib
- Division of Endocrinology and Metabolism, Loyola University Medical Center, Maywood, IL, USA
| | - Nicholas V Emanuele
- Division of Endocrinology and Metabolism, Loyola University Medical Center, Maywood, IL, USA; Endocrinology Section, Edward Hines Jr. VA Hospital, Hines, IL, USA
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14
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Rahmat N, Venables P. Sinus pauses and high-grade atrioventricular block in Albright's hereditary osteodystrophy with pseudopseudohypoparathyroidism. BMJ Case Rep 2013; 2013:bcr-2013-010116. [PMID: 23814007 DOI: 10.1136/bcr-2013-010116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Albright's hereditary osteodystrophy (AHO) is a rare inherited syndrome involving the molecular defects in the gene encoding the α subunit of the stimulatory G protein (Gsα). AHO has several variants, mainly pseudohypoparathyroidism (PHP) and pseudopseudohypoparathyroidism (PPHP). We present a family that share the same inactivating GNAS1 mutation, the daughter being affected by PPHP and her late father with PHP. The daughter, in her late teens, presented with a long history of presyncopal and syncopal attacks. Her father died suddenly in his mid-40 s. As expected, her laboratory tests to date have shown normal biochemistry and hormonal levels. Subsequently, an implantable loop recorder was inserted. This demonstrated extreme sinus pauses of >11 s and also high-grade atrioventricular block. A dual-chamber pacemaker was therefore inserted.
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Affiliation(s)
- N Rahmat
- Department of Cardiology, Ipswich Hospital, Ipswich, UK.
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15
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Cheeseman MT, Vowell K, Hough TA, Jones L, Pathak P, Tyrer HE, Kelly M, Cox R, Warren MV, Peters J. A mouse model for osseous heteroplasia. PLoS One 2012; 7:e51835. [PMID: 23284784 PMCID: PMC3526487 DOI: 10.1371/journal.pone.0051835] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 11/07/2012] [Indexed: 11/29/2022] Open
Abstract
GNAS/Gnas encodes Gsα that is mainly biallelically expressed but shows imprinted expression in some tissues. In Albright Hereditary Osteodystrophy (AHO) heterozygous loss of function mutations of GNAS can result in ectopic ossification that tends to be superficial and attributable to haploinsufficiency of biallelically expressed Gsα. Oed-Sml is a point missense mutation in exon 6 of the orthologous mouse locus Gnas. We report here both the late onset ossification and occurrence of benign cutaneous fibroepithelial polyps in Oed-Sml. These phenotypes are seen on both maternal and paternal inheritance of the mutant allele and are therefore due to an effect on biallelically expressed Gsα. The ossification is confined to subcutaneous tissues and so resembles the ossification observed with AHO. Our mouse model is the first with both subcutaneous ossification and fibroepithelial polyps related to Gsα deficiency. It is also the first mouse model described with a clinically relevant phenotype associated with a point mutation in Gsα and may be useful in investigations of the mechanisms of heterotopic bone formation. Together with earlier results, our findings indicate that Gsα signalling pathways play a vital role in repressing ectopic bone formation.
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Affiliation(s)
- Michael T Cheeseman
- Medical Research Council Mammalian Genetics Unit, Medical Research Council Harwell, Oxfordshire, UK.
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16
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Izzi B, Francois I, Labarque V, Thys C, Wittevrongel C, Devriendt K, Legius E, Van den Bruel A, D'Hooghe M, Lambrechts D, de Zegher F, Van Geet C, Freson K. Methylation defect in imprinted genes detected in patients with an Albright's hereditary osteodystrophy like phenotype and platelet Gs hypofunction. PLoS One 2012; 7:e38579. [PMID: 22679513 PMCID: PMC3367970 DOI: 10.1371/journal.pone.0038579] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 05/07/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Pseudohypoparathyroidism (PHP) indicates a group of heterogeneous disorders whose common feature is represented by impaired signaling of hormones that activate Gsalpha, encoded by the imprinted GNAS gene. PHP-Ib patients have isolated Parathormone (PTH) resistance and GNAS epigenetic defects while PHP-Ia cases present with hormone resistance and characteristic features jointly termed as Albright's Hereditary Osteodystrophy (AHO) due to maternally inherited GNAS mutations or similar epigenetic defects as found for PHP-Ib. Pseudopseudohypoparathyroidism (PPHP) patients with an AHO phenotype and no hormone resistance and progressive osseous heteroplasia (POH) cases have inactivating paternally inherited GNAS mutations. METHODOLOGY/PRINCIPAL FINDINGS We here describe 17 subjects with an AHO-like phenotype that could be compatible with having PPHP but none of them carried Gsalpha mutations. Functional platelet studies however showed an obvious Gs hypofunction in the 13 patients that were available for testing. Methylation for the three differentially methylated GNAS regions was quantified via the Sequenom EpiTYPER. Patients showed significant hypermethylation of the XL amplicon compared to controls (36 ± 3 vs. 29 ± 3%; p<0.001); a pattern that is reversed to XL hypomethylation found in PHPIb. Interestingly, XL hypermethylation was associated with reduced XLalphaS protein levels in the patients' platelets. Methylation for NESP and ExonA/B was significantly different for some but not all patients, though most patients have site-specific CpG methylation abnormalities in these amplicons. Since some AHO features are present in other imprinting disorders, the methylation of IGF2, H19, SNURF and GRB10 was quantified. Surprisingly, significant IGF2 hypermethylation (20 ± 10 vs. 14 ± 7%; p<0.05) and SNURF hypomethylation (23 ± 6 vs. 32 6%; p<0.001) was found in patients vs. controls, while H19 and GRB10 methylation was normal. CONCLUSION/SIGNIFICANCE In conclusion, this is the first report of methylation defects including GNAS in patients with an AHO-like phenotype without endocrinological abnormalities. Additional studies are still needed to correlate the methylation defect with the clinical phenotype.
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Affiliation(s)
- Benedetta Izzi
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Inge Francois
- Departement of Pediatrics, University of Leuven, Leuven, Belgium
| | - Veerle Labarque
- Departement of Pediatrics, University of Leuven, Leuven, Belgium
| | - Chantal Thys
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | | | - Koen Devriendt
- Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - Eric Legius
- Center for Human Genetics, University of Leuven, Leuven, Belgium
| | | | | | | | | | - Chris Van Geet
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
- Departement of Pediatrics, University of Leuven, Leuven, Belgium
| | - Kathleen Freson
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
- * E-mail:
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17
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No evidence for GNAS copy number variants in patients with features of Albright's hereditary osteodystrophy and abnormal platelet Gs activity. J Hum Genet 2012; 57:277-9. [PMID: 22277900 DOI: 10.1038/jhg.2012.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Albright's hereditary osteodystrophy (AHO) is characterized by short stature, round face, calcifications, obesity, brachydactyly and intellectual disability. AHO without hormone resistance is called pseudopseudohypoparathyroidism (PPHP), a rare clinical condition difficult to diagnose with highly variable features. PPHP is caused by paternally inherited loss-of-function mutations in the GNAS. Patients with 2q37 microdeletions or HDAC4 mutations are also defined as having an AHO-like phenotype with normal stimulatory G (Gs) function. We have studied 256 patients with AHO features but no other diagnosis. Their platelet Gs activity was determined via the aggregation-inhibition test showing Gs hypo- or hyperfuncton in 24% and 15% of the patients, respectively. Before initiating with detailed (epi)genetic GNAS studies, we here wanted to excluded copy number variants (CNVs) in GNAS as cause of AHO with a novel large-scale screening technique. Multiplex amplicon quantification (MAQ) for CNVs screening was developed for the 20q13.3 region including GNAS and potential long-range imprinting control elements such as STX16. This is the first large-scale GNAS CNV study in patients with common AHO features but no CNVs were detected. In conclusion, CNVs in the GNAS region are not likely to cause an AHO-like phenotype with or without abnormal platelet Gs activity. Future studies will be undertaken to find out whether these AHO patients with abnormal Gs function are characterized by GNAS coding or methylation defects.
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18
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Crane JL, Shamblott MJ, Axelman J, Hsu S, Levine MA, Germain-Lee EL. Imprinting status of Galpha(s), NESP55, and XLalphas in cell cultures derived from human embryonic germ cells: GNAS imprinting in human embryonic germ cells. Clin Transl Sci 2010; 2:355-60. [PMID: 20443919 DOI: 10.1111/j.1752-8062.2009.00148.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
GNAS is a complex gene that through use of alternative first exons encodes signaling proteins Galpha(s) and XLalphas plus neurosecretory protein NESP55. Tissue-specific expression of these proteins is regulated through reciprocal genomic imprinting in fully differentiated and developed tissue. Mutations in GNAS account for several human disorders, including McCune-Albright syndrome and Albright hereditary osteodystrophy, and further knowledge of GNAS imprinting may provide insights into variable phenotypes of these disorders. We therefore analyzed expression of Galpha(s), NESP55, and XLalphas prior to tissue differentiation in cell cultures derived from human primordia germ cells. We found that the expression of Galpha(s) was biallelic (maternal allele: 52.6%+/- 2.5%; paternal allele: 47.2%+/- 2.5%; p= 0.07), whereas NESP55 was expressed preferentially from the maternal allele (maternal allele: 81.9%+/- 10%; paternal allele: 18.1%+/- 10%; p= 0.002) and XLalphas was preferentially expressed from the paternal allele (maternal allele: 2.7%+/- 0.3%; paternal allele: 97.3%+/- 0.3%; p= 0.007). These results demonstrate that imprinting of NESP55 occurs very early in development, although complete imprinting appears to take place later than 5-11 weeks postfertilization, and that imprinting of XLalphas occurs very early postfertilization. By contrast, imprinting of Galpha(s) most likely occurs after 11 weeks postfertilization and after tissue differentiation.
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Affiliation(s)
- Janet L Crane
- Department of Pediatrics, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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19
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Kelsey G. Imprinting on chromosome 20: Tissue-specific imprinting and imprinting mutations in the GNAS locus. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2010; 154C:377-86. [DOI: 10.1002/ajmg.c.30271] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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20
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Abstract
Human imprinting disorders can provide critical insights into the role of imprinted genes in human development and health, and the molecular mechanisms that regulate genomic imprinting. To illustrate these concepts we review the clinical and molecular features of several human imprinting syndromes including Beckwith–Wiedemann syndrome, Silver–Russell syndrome, Angelman syndrome, Prader–Willi syndrome, pseudohypoparathyroidism, transient neonatal diabetes, familial complete hydatidiform moles and chromosome 14q32 imprinting domain disorders.
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Affiliation(s)
- Derek HK Lim
- Birmingham Women’s Hospital, Birmingham UK
- Department of Medical & Molecular Genetics, School of Clinical and Experimental Medicine, University of Birmingham College of Medical and Dental Sciences, Edgbaston, Birmingham, B15 2TT, UK
| | - Eamonn R Maher
- Birmingham Women’s Hospital, Birmingham UK
- Department of Medical & Molecular Genetics, School of Clinical and Experimental Medicine, University of Birmingham College of Medical and Dental Sciences, Edgbaston, Birmingham, B15 2TT, UK
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21
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Two children with subtelomeric 11q deletions: a description and interpretation of their clinical presentations and molecular genetic findings. Clin Dysmorphol 2009; 18:98-102. [DOI: 10.1097/mcd.0b013e3283202a1f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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22
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Avenel G, Bernet J, Lahaxe L, Lévesque H, Marie I. [Subcutaneous calcifications and dysmorphic syndrome]. Rev Med Interne 2009; 31:238-40. [PMID: 19329231 DOI: 10.1016/j.revmed.2009.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 02/02/2009] [Indexed: 10/21/2022]
Affiliation(s)
- G Avenel
- Département de médecine interne, CHU de Rouen, France
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23
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Freson K, Izzi B, Labarque V, Van Helvoirt M, Thys C, Wittevrongel C, Bex M, Bouillon R, Godefroid N, Proesmans W, de Zegher F, Jaeken J, Van Geet C. GNAS defects identified by stimulatory G protein alpha-subunit signalling studies in platelets. J Clin Endocrinol Metab 2008; 93:4851-9. [PMID: 18812479 DOI: 10.1210/jc.2008-0883] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
CONTEXT GNAS is an imprinted region that gives rise to several transcripts, antisense transcripts, and noncoding RNAs, including transcription of RNA encoding the alpha-subunit of the stimulatory G protein (Gsalpha). The complexity of the GNAS cluster results in ubiquitous genomic imprints, tissue-specific Gsalpha expression, and multiple genotype-phenotype relationships. Phenotypes resulting from genetic and epigenetic abnormalities of the GNAS region include Albright's hereditary osteodystrophy, pseudohypoparathyroidism types Ia (PHPIa) and Ib (PHPIb), and pseudopseudohypoparathyroidism (PPHP). OBJECTIVE The aim was to study the complex GNAS pathology by a functional test as an alternative to the generally used but labor-intensive erythrocyte complementation assay. DESIGN AND PATIENTS We report the first platelet-based diagnostic test for Gsalpha hypofunction, supported by clinical, biochemical, and molecular data for six patients with PHPIa or PPHP and nine patients with PHPIb. The platelet test is based on the inhibition of platelet aggregation by cAMP, produced after Gsalpha stimulation. RESULTS Platelets are easily accessible, and platelet aggregation responses were found to reflect Gsalpha signaling defects in patients, in concordance with the patient's phenotype and genotype. Gsalpha hypofunction in PHPIa and PPHP patients with GNAS mutations was clearly detected by this method. Mildly decreased or normal Gsalpha function was detected in patients with PHPIb with either an overall or exon 1A-only epigenetic defect, respectively. Platelet Gsalpha expression was reduced in both PHPIb patient groups, whereas XLalphas was up-regulated only in PHPIb patients with the broad epigenetic defect. CONCLUSION The platelet-based test is a novel tool for establishing the diagnosis of Gsalpha defects, which may otherwise be quite challenging.
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Affiliation(s)
- Kathleen Freson
- Center for Molecular and Vascular Biology, University of Leuven, Herestraat 49, B-3000 Leuven, Belgium.
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24
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Abstract
Pseudohypoparathyroidism (PHP) types Ia and Ic result from heterozygous inactivating mutations of Gs alpha, the alpha-subunit of the heterotrimeric stimulatory G-protein, Gs. Both are characterized by a combination of Albright's hereditary osteodystrophy and, when the mutation is maternally inherited, end-organ resistance to multiple hormones. Due to complex tissue-specific imprinting of Gs alpha, paternally-derived mutations do not usually lead to hormone resistance. More than 100 mutations have been characterized in patients with PHP-Ia and one mutation in type Ic. These are scattered throughout the gene, with one significant mutational hotspot in exon 7. Identification of mutations in a clinical service setting is important for accurate genetic counselling and clinical management of affected families. However, only 70-80% of mutations are identified by direct sequencing of coding exons and splice junctions. Screening for whole exon deletions and intronic or regulatory mutations in mutation-negative families is therefore now an important priority to establish the full mutational spectrum in these conditions.
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Affiliation(s)
- Micheala A Aldred
- Division of Medical Genetics, University of Leicester and Leicestershire Genetics Service, University Hospitals of Leicester NHS Trust, Leicester, UK.
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25
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Germain-Lee EL, Schwindinger W, Crane JL, Zewdu R, Zweifel LS, Wand G, Huso DL, Saji M, Ringel MD, Levine MA. A mouse model of albright hereditary osteodystrophy generated by targeted disruption of exon 1 of the Gnas gene. Endocrinology 2005; 146:4697-709. [PMID: 16099856 DOI: 10.1210/en.2005-0681] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Albright hereditary osteodystrophy is caused by heterozygous inactivating mutations in GNAS, a gene that encodes not only the alpha-chain of Gs (Galphas), but also NESP55 and XLalphas through use of alternative first exons. Patients with GNAS mutations on maternally inherited alleles are resistant to multiple hormones such as PTH, TSH, LH/FSH, GHRH, and glucagon, whose receptors are coupled to Gs. This variant of Albright hereditary osteodystrophy is termed pseudohypoparathyroidism type 1a and is due to presumed tissue-specific paternal imprinting of Galphas. Previous studies have shown that mice heterozygous for a targeted disruption of exon 2 of Gnas, the murine homolog of GNAS, showed unique phenotypes dependent on the parent of origin of the mutated allele. However, hormone resistance occurred only when the disrupted gene was maternally inherited. Because disruption of exon 2 is predicted to inactivate Galphas as well as NESP55 and XLalphas, we created transgenic mice with disruption of exon 1 to investigate the effects of isolated loss of Galphas. Heterozygous mice that inherited the disruption maternally (-m/+) exhibited PTH and TSH resistance, whereas those with paternal inheritance (+/-p) had normal hormone responsiveness. Heterozygous mice were shorter and, when the disrupted allele was inherited maternally, weighed more than wild-type littermates. Galphas protein and mRNA expression was consistent with paternal imprinting in the renal cortex and thyroid, but there was no imprinting in renal medulla, heart, or adipose. These findings confirm the tissue-specific paternal imprinting of GNAS and demonstrate that Galphas deficiency alone is sufficient to account for the hormone resistance of pseudohypoparathyroidism type 1a.
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Affiliation(s)
- Emily L Germain-Lee
- Division of Pediatric Endocrinology, Department of Pediatrics, The Johns Hopkins University School of Medicine, Park Building, Suite 211, 600 North Wolfe Street, Baltimore, Maryland 21287-2520, USA.
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Abstract
Penetrance and expressivity have been defined through clinical experience. Although penetrance is often seen as the end of the spectrum of expressivity, penetrance and expressivity are considered as distinct phenomena. A review of the known mechanisms underlying either penetrance or expressivity reveals that in most of the cases the same explanation is true for both phenomena. Some of the known mechanisms include modifier genes, the influence of the allele in trans, sex, and environmental factors. Although rapid progress has been made in understanding of the basis of incomplete penetrance and the differences of expressivity, they still remain unknown for most of the genetic disorders. In recent years, it has become evident that there is much in common between the classical Mendelian traits in which the inheritance has been seen as "simple" and most of the common diseases in which the inheritance is "complex." In both cases genetic and/or environmental factors are acting in a complex way.
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Affiliation(s)
- Joël Zlotogora
- Department of Community Genetics, Public Health Services, Ministry of Health, Israel
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27
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Rickard SJ, Wilson LC. Analysis of GNAS1 and overlapping transcripts identifies the parental origin of mutations in patients with sporadic Albright hereditary osteodystrophy and reveals a model system in which to observe the effects of splicing mutations on translated and untranslated messenger RNA. Am J Hum Genet 2003; 72:961-74. [PMID: 12624854 PMCID: PMC1180358 DOI: 10.1086/374566] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2002] [Accepted: 01/16/2003] [Indexed: 11/03/2022] Open
Abstract
Albright hereditary osteodystrophy (AHO) is caused by heterozygous deactivating GNAS1 mutations. There is a parent-of-origin effect. Maternally derived mutations are usually associated with resistance to parathyroid hormone termed "pseudohypoparathyroidism type Ia." Paternally derived mutations are associated with AHO but usually normal hormone responsiveness, known as "pseudo-pseudohypoparathyroidism." These observations can be explained by tissue-specific GNAS1 imprinting. Regulation of the genomic region that encompasses GNAS1 is complex. At least three upstream exons that splice to exon 2 of GNAS1 and that are imprinted have been reported. NESP55 is exclusively maternally expressed, whereas exon 1A and XL alphas are exclusively paternally expressed. We set out to identify the parental origin of GNAS1 mutations in patients with AHO by searching for their mutation in the overlapping transcripts. This information would be of value in patients with sporadic disease, for predicting their endocrine phenotype and planning follow-up. In doing so, we identified mutations that resulted in nonsense-mediated decay of the mutant Gs alpha transcript but that were detectable in NESP55 messenger RNA (mRNA), probably because they lie within its 3' untranslated region. Analysis of the NESP55 transcripts revealed the creation of a novel splice site in one patient and an unusual intronic mutation that caused retention of the intron in a further patient, neither of which could be detected by analysis of the Gs alpha complementary DNA. This cluster of overlapping transcripts represents a useful model system in which to analyze the effects that mutant sequence has on mRNA-in particular, splicing-and the mechanisms of nonsense-mediated mRNA decay.
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Affiliation(s)
- Sarah J Rickard
- Clinical and Molecular Genetics Unit, Institute of Child Health, and Great Ormond Street Hospital NHS Trust, London, United Kingdom
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28
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Rozendaal L, Del Canho H, Waterham HR, Hennekam RCM. Midface hypoplasia, obesity, developmental delay and neonatal hypotonia in two brothers. Clin Dysmorphol 2003; 12:9-13. [PMID: 12514359 DOI: 10.1097/00019605-200301000-00002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We describe two brothers born to consanguineous parents, who presented with hypotonia and hypoglycaemia in the neonatal period and later developed obesity and developmental delay. They had brachydactyly and similar facial features including a prominent forehead, low nasal bridge, midface hypoplasia, full lips, a small mouth, and small, low set ears with overfolded helices. Their sister had mild learning disabilities. No additional anomalies were found, and metabolic investigations including peroxisomal functions gave normal results. We suggest the patients have a hitherto unreported condition, with an autosomal or X-linked mode of inheritance.
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Affiliation(s)
- Lieke Rozendaal
- Department of Pediatrics and Clinical Genetics, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, the Netherlands
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29
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Aldred MA, Aftimos S, Hall C, Waters KS, Thakker RV, Trembath RC, Brueton L. Constitutional deletion of chromosome 20q in two patients affected with albright hereditary osteodystrophy. AMERICAN JOURNAL OF MEDICAL GENETICS 2002; 113:167-72. [PMID: 12407707 DOI: 10.1002/ajmg.10751] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Albright hereditary osteodystrophy (AHO) results from heterozygous inactivation of G(s)alpha, encoded by the GNAS1 locus on the distal long arm of chromosome 20. This autosomal dominant condition is characterized by short stature, obesity, shortening of the metacarpals and metatarsals, and variable mental retardation and may also include end-organ resistance to multiple hormones. Small insertions and deletions or point mutations of GNAS1 are found in approximately 80% of patients with AHO. The remainder may be accounted for by larger genomic rearrangements, but none have been reported to date. We now describe two patients with constitutional 20q deletions and features of AHO. Such deletions are rare in the published literature and have not previously been associated with AHO. Molecular genetic analysis confirmed complete deletion of GNAS1 in both patients. Parental origin could be determined in both cases and provides further support for the parent-of-origin effect on the biochemical status of patients with AHO.
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Affiliation(s)
- Micheala A Aldred
- Division of Medical Genetics, University of Leicester, and Department of Molecular Genetics, University Hospitals of Leicester NHS Trust, Leicester, UK.
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30
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Germain-Lee EL, Ding CL, Deng Z, Crane JL, Saji M, Ringel MD, Levine MA. Paternal imprinting of Galpha(s) in the human thyroid as the basis of TSH resistance in pseudohypoparathyroidism type 1a. Biochem Biophys Res Commun 2002; 296:67-72. [PMID: 12147228 DOI: 10.1016/s0006-291x(02)00833-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Albright hereditary osteodystrophy (AHO) is characterized by multiple somatic defects secondary to mutations in the GNAS1 gene. AHO patients with mutations on maternally inherited alleles are resistant to multiple hormones (e.g., PTH, TSH), a variant termed pseudohypoparathyroidism (PHP) type 1a, due to presumed tissue-specific paternal imprinting of the alpha chain of G(s) as demonstrated in murine renal proximal tubule and fat cells. Studies in human tissues thus far revealed imprinting only in pituitary. Because mild hypothyroidism due to TSH resistance occurs in most PHP type 1a patients, we investigated whether Galpha(s) is imprinted in thyroid. Examination of eight normal thyroids demonstrated significantly greater expression from the maternal GNAS1 allele, with paternal Galpha(s) transcripts accounting for only 25.9-40.4%. Expression of NESP55, XLalpha(s), and 1A was uniallelic. We conclude that Galpha(s) is incompletely imprinted in the thyroid, which provides an explanation for mild TSH resistance in PHP type 1a.
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Affiliation(s)
- Emily L Germain-Lee
- Division of Pediatric Endocrinology, Department of Pediatrics, The Johns Hopkins University School of Medicine, Park Building, Suite 211, 600 N. Wolfe Street, Baltimore, 21287-2520, MD, USA.
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31
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Abstract
Genetic modifications of imprinted genes have been generated in the mouse to investigate the regulation of their expression. They show classical imprinted gene inheritances. Here we describe two imprinted gene mutations deriving from mutagenesis experiments. One is expressed only when transmitted through males. It causes a prenatal growth retardation which resembles that of the Igf2 knockout and maps close to the locus on chromosome 7. Differences from the knockout, which include an abnormal head phenotype, homozygous lethality, and an inability to rescue a TME: (Igf2r-deficient) lethality, suggest that Igf2 itself may not be directly affected. The second mutation maps close to the GNAS: cluster of imprinted genes on distal chromosome 2. It gives two distinct phenotypes according to parental origin, a gross neonatal oedema with microcardia and a postnatal growth retardation. The oedema phenotype is effectively lethal and resembles that of mice with paternal partial disomy for distal chromosome 2, as well as that of mice having a maternally derived GNAS: exon 2 knockout. However, the second growth retardation phenotype differs from that of the maternal partial disomy and the paternal knockout. A hypothesis to explain the phenotypes associated with the three genotypes based on the NESP:/NESPAS: sense/antisense and GNASXL: transcripts in the GNAS: cluster is offered.
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Affiliation(s)
- B M Cattanach
- Medical Research Council, Mammalian Genetics Unit, Harwell, Didcot, Oxfordshire OX11 0RD, UK.
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32
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Abstract
GNAS1 on chromosome 20 is a complex locus, encoding multiple proteins, of which G(s)alpha, the alpha-subunit of the heterotrimeric stimulatory G protein G(s), is of particular interest clinically. Amino acid substitutions at two specific codons lead to constitutive activation of G(s)alpha. Such gain-of-function mutations are found in a variety of sporadic endocrine tumors and in McCune-Albright syndrome, a sporadic condition characterized by multiple endocrine abnormalities. Heterozygous loss of G(s)alpha function results in the dominantly inherited condition, Albright hereditary osteodystrophy (AHO). Here we present a review of published GNAS1 mutations and report 19 additional mutations, of which 15 are novel. A diverse range of inactivating mutations has been detected, scattered throughout the gene but showing some evidence of clustering. Only one, a recurring 4 bp deletion in exon 7, could be considered common among AHO patients. The parental origin of the mutation apparently determines whether or not the patient shows end-organ resistance to hormones such as parathyroid hormone. G(s)alpha is biallelically expressed in all tissues studied to date and thus there is no direct evidence that this transcript is imprinted. However, the recent identification of other imprinted transcripts encoded by GNAS1 and overlapping G(s)alpha, together with at least one imprinted antisense transcript, raises intriguing questions about how the primary effect of mutations in GNAS1 might be modulated.
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Affiliation(s)
- M A Aldred
- Leicestershire Genetics Centre, Leicester Royal Infirmary, Leicester, UK
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33
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Speleman F, Callens B, Logghe K, Van Roy N, Horsley SW, Jauch A, Verschraegen-Spae MR, Leroy JG. Subtelomeric familial translocation t(2;7)(q37;q35) leading to partial trisomy 7q35?qter: Molecular cytogenetic analysis and clinical phenotype in two generations. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/1096-8628(20000828)93:5<349::aid-ajmg2>3.0.co;2-s] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kelsey G, Bodle D, Miller HJ, Beechey CV, Coombes C, Peters J, Williamson CM. Identification of imprinted loci by methylation-sensitive representational difference analysis: application to mouse distal chromosome 2. Genomics 1999; 62:129-38. [PMID: 10610704 DOI: 10.1006/geno.1999.6022] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Imprinted genes are distinguished by different patterns of methylation on their parental alleles, a property by which imprinted loci could be identified systematically. Here, representational difference analysis (RDA) is used to clone HpaII fragments with methylation differences on the maternal and paternal copies of distal chromosome (Chr) 2 in the mouse. Uniparental inheritance for this region causes imprinting phenotypes whose molecular basis is only partially understood. RDA led to the recovery of multiple differentially methylated HpaII fragments at two major sites of imprinted methylation: paternal-specific methylation at the Nesp locus and maternal-specific methylation at the Gnasxl locus. Nesp and Gnasxl represent oppositely imprinted promoters of the Gnas gene, which encodes the G-protein subunit, Gsalpha. The organization of the Nesp-Gnasxl-Gnas region was determined: Nesp and Gnasxl were found to be 15 kb apart, and Gnasxl was found to be 30 kb upstream of Gnas. Sites of imprinted methylation were also detected at the loci for neuronatin on Chr 2 and for M-cadherin on Chr 8. RDA was highly effective at identifying imprinted methylation, and its potential applications to imprinting studies are discussed.
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Affiliation(s)
- G Kelsey
- Developmental Genetics Programme, The Babraham Institute, Cambridge, United Kingdom.
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35
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Bijlsma EK, Aalfs CM, Sluitjer S, Oude Luttikhuis ME, Trembath RC, Hoovers JM, Hennekam RC. Familial cryptic translocation between chromosomes 2qter and 8qter: further delineation of the Albright hereditary osteodystrophy-like phenotype. J Med Genet 1999; 36:604-9. [PMID: 10465110 PMCID: PMC1762967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Recently five patients with an Albright hereditary osteodystrophy (AHO)-like phenotype were reported to have a subtelomeric deletion of the long arm of chromosome 2. These patients showed a striking resemblance to a number of patients from a large pedigree known to us for a long time. After molecular confirmation of a subtelomeric deletion in one patient, FISH analysis was used and a cryptic translocation between the long arms of chromosomes 2 and 8, t(2;8)(q37.3;q24.3), was detected. Remarkably, five proven and 10 probable cases with a 2qter deletion were found in the family, but none with an 8qter deletion. This was not explained by increased fetal loss. The major clinical characteristics of terminal 2q deletion are a short, stocky build, round face, sparse hair, deeply set eyes, bulbous nose, thin vermilion border, brachymetaphalangism, seizures, and developmental delay. A specific behavioural phenotype consisting of periods of hyperkinesia and aggression can develop with age. The overall phenotype is sufficiently characteristic to allow clinical recognition. The cytogenetic and molecular studies did not narrow down the common deleted region. Both testing of additional 2q markers and characterisation of other AHO-like patients with 2q37 microdeletions may help to define the candidate gene region.
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Affiliation(s)
- E K Bijlsma
- Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, The Netherlands
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36
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Abstract
It has been demonstrated that the majority of secreting and nonsecreting adenomas is monoclonal in origin suggesting that these neoplasia arise from the replication of a single mutated cell, in which growth advantage results from either activation of protooncogenes or inactivation of antioncogenes. Although a large number of genes has been screened for mutations, only few genetic abnormalities have been found in pituitary tumors such as allelic deletion of chromosome 11q13 where the MEN-1 gene has been localised, and mutations in the gene encoding the alpha subunit of the stimulatory Gs and Gi2 protein. These mutations constitutively activate the alpha subunit of the Gs and Gi2 protein by inhibiting their intrinsic GTPase activity. Both Gs alpha and Gi2alpha can be considered products of protooncogenes (gsp and gip2, respectively) since gain of function mutations that activate mitogenic signals have been recognized in human tumors. Gsp oncogene is found in 30-40% of GH-secreting adenomas, in a low percentage of nonfunctioning and ACTH-secreting pituitary adenomas, in toxic thyroid adenomas and differentiated thyroid carcinomas. The same mutations, occurred early in embriogenesis, have been also identified in tissues from patients affected with the McCune Albright syndrome. These mutations result in an increased cAMP production and in the subsequent overactivation of specific pathways involved in both cell growth and specific programmes of cell differentiation. By consequence, the endocrine tumors expressing gsp oncogene retain differentiated functions. The gip2 oncogene has been identified in about 10% of nonfunctioning pituitary adenomas, in tumors of the ovary and the adrenal cortex. However, it remains to be established whether Gi proteins activate mitogenic signals in pituitary cells. Since Gi proteins are involved in mediating the effect of inhibitory neurohormones on intracellular effectors, it has been proposed that in pituitary tumors the low expression of these proteins, particularly Gi1-3alpha, may contribute to uncontrolled pituitary cells growth by preventing the transduction of inhibitory signals. While by in vitro mutagenesis it has been demonstrated that activated mutant of Gq alpha, G12alpha, G13alpha and Gz alpha are fully oncogenic, it remains to be proved whether or not these abnormalities might naturally occur in human tumors and, in particular, in pituitary adenomas.
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Affiliation(s)
- A Spada
- Institute of Endocrine Sciences, University of Milan, Ospedale Maggiore IRCCS, Milano, Italy.
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Namnoum AB, Merriam GR, Moses AM, Levine MA. Reproductive dysfunction in women with Albright's hereditary osteodystrophy. J Clin Endocrinol Metab 1998; 83:824-9. [PMID: 9506735 DOI: 10.1210/jcem.83.3.4652] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Most individuals with Albright's hereditary osteodystrophy (AHO) have deficient expression or function of G(s alpha), the alpha subunit of the guanine nucleotide binding protein that stimulates adenylyl cyclase, and are resistant to parathyroid hormone (PTH) and other hormones that act via stimulation of adenylyl cyclase. To determine the incidence and etiology of ovarian dysfunction in women with AHO, we examined the reproductive history and hypothalamic-pituitary-ovarian axis in 17 affected women aged 17-43 yr. All patients had typical PTH resistance and an approximately 50% reduction in erythrocyte G(s alpha) activity, (0.43 +/- 0.03 vs. 0.92 +/- 0.08 for normal control subjects, P < 0.001). Fourteen of the 17 patients (76%) were oligomenorrheic or amenorrheic, more than half had delayed or incomplete sexual development, and only two had a history of earlier pregnancy. Most women were mildly hypoestrogenic, with normal to slightly elevated serum gonadotropin levels. Computer analysis of 24 hour LH measurement showed that the frequency of LH peaks/24 h in AHO women varied widely, but as a group they were not statistically different from a group of normal women studied in the early follicular phase. Administration of 100 microg synthetic GnRH produced normal FSH and LH responses. We conclude that reproductive dysfunction is common in women with AHO and probably represents partial resistance to gonadotropins.
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Affiliation(s)
- A B Namnoum
- Department of Gynecology and Obstetrics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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38
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Power MM, James RS, Barber JC, Fisher AM, Wood PJ, Leatherdale BA, Flanagan DE, Hatchwell E. RDCI, the vasoactive intestinal peptide receptor: a candidate gene for the features of Albright hereditary osteodystrophy associated with deletion of 2q37. J Med Genet 1997; 34:287-90. [PMID: 9138150 PMCID: PMC1050913 DOI: 10.1136/jmg.34.4.287] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Albright hereditary osteodystrophy (AHO) is an autosomal dominant disorder characterised by the presence of brachymetaphalangism, short stature, obesity, and mental retardation. Variable biochemical changes many represent either pseudohypoparathyroidism (PHP) owing to resistance to parathormone (PTH) or pseudopseudohypoparathyroidism (PPHP) with no hormone resistance. In most cases of AHO, reduced levels of Gs alpha have been found and a number of deactivating mutations in the gene for Gs alpha located on chromosome 20q13 have been described. Recently a number of people with an AHO-like phenotype have been reported in whom a deletion of chromosomal region 2q37 has been found in the absence of biochemical abnormalities or a reduction in Gs alpha activity. We present a further female patient with a cytogenetically visible deletion of 2q37, an AHO-like phenotype, and unusual biochemistry suggesting moderate PTH resistance. The vasoactive intestinal peptide receptor (RDCI) has recently been mapped to 2q37 and we propose that this is a candidate gene, hemizygosity of which affects signal transduction and leads to the AHO-like phenotype found in patients with 2q37 deletions.
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Affiliation(s)
- M M Power
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, UK
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Wilson LC, Oude Luttikhuis ME, Baraitser M, Kingston HM, Trembath RC. Normal erythrocyte membrane Gs alpha bioactivity in two unrelated patients with acrodysostosis. J Med Genet 1997; 34:133-6. [PMID: 9039990 PMCID: PMC1050867 DOI: 10.1136/jmg.34.2.133] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Shortening of the tubular bones of the hands and feet with cone shaped epiphyses is known as peripheral dysostosis and is common to several syndromes including acrodysostosis and Albright's hereditary osteodystrophy (AHO). The underlying defect in AHO is known to be a reduction in bioactivity of the alpha subunit of the signal transducing protein, Gs, and heterozygous deactivating mutations have been shown in the Gs alpha gene. Because of additional overlapping clinical and radiological features it has been suggested that acrodysostosis and AHO represent poles of a single diagnostic spectrum. We have measured Gs alpha bioactivity in two unrelated patients with a clinical diagnosis of acrodysostosis and found both to be normal. Mutation analysis of the Gs alpha gene showed no sequence variation in 12 of the 13 exons examined. These results indicate that, at least in a proportion of patients with acrodysostosis, the condition is aetiologically distinct from AHO.
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Affiliation(s)
- L C Wilson
- Department of Medicine, University of Leicester, UK
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40
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Strautnieks SS, Thompson RJ, Hanukoglu A, Dillon MJ, Hanukoglu I, Kuhnle U, Seckl J, Gardiner RM, Chung E. Localisation of pseudohypoaldosteronism genes to chromosome 16p12.2-13.11 and 12p13.1-pter by homozygosity mapping. Hum Mol Genet 1996; 5:293-9. [PMID: 8824886 DOI: 10.1093/hmg/5.2.293] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Pseudohypoaldosteronism type 1 (PHA1, OMIM 264350) is a rare Mendelian disorder characterised by end-organ unresponsiveness to mineralocorticoids. Most steroid hormone insensitivity syndromes arise from mutations in the corresponding receptor, but available genetic evidence is against involvement of the mineralocorticoid receptor gene, MLR, in PHA1. A complete genome scan for PHA1 genes was undertaken using homozygosity mapping in 11 consanguineous families. Conclusive evidence of linkage with heterogeneity was obtained with a maximum two-locus admixture lod score of 9.9. The disease locus mapped to chromosome 16p12.2-13.11 in six families and to 12p13.1-pter in the other five families. The two chromosomal regions harbour genes for subunits of the amiloride-sensitive epithelial sodium channel: SCNN1B and SCNN1G on 16p and SCNN1A on 12p. Liddle's syndrome of hypertension and pseudoaldosteronism has been shown to arise from mutations in SCNN1B and SCNN1G. These results strongly suggest that PHA1 and Liddle's syndrome are allelic variants caused by mutations in genes encoding subunits of this sodium channel. These genes are of broad biological interest both in relation to sodium and water homeostasis in mammals and by virtue of their homology to the mec genes of Caenorhabditis elegans involved in mechanosensitivity and neuronal degeneration.
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Affiliation(s)
- S S Strautnieks
- Department of Paediatrics, University College London Medical School, UK
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