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Tang W, Wu K, Zhou Q, Tang Y, Fu J, Dong G, Zou C. Genotype and phenotype in patients with ACAN gene variants: Three cases and literature review. Mol Genet Genomic Med 2024; 12:e2439. [PMID: 38613222 PMCID: PMC11015147 DOI: 10.1002/mgg3.2439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 03/25/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
OBJECTIVE To characterize the phenotype spectrum, diagnosis, and response to growth-promoting therapy in patients with ACAN variants causing familial short stature. METHODS Three families with ACAN variants causing short stature were reported. Similar cases in the literature were summarized, and the genotype and phenotype were analyzed. RESULTS Three novel heterozygous variants, c.757+1G>A, (splicing), c.6229delG, p.(Asp2078Tfs*1), and c.6679C>T, p.(Gln2227*) in the ACAN gene were identified. A total of 314 individuals with heterozygous variants from 105 families and 8 individuals with homozygous variants from 4 families were confirmed to have ACAN variants from literature and our 3 cases. Including our 3 cases, the variants reported comprised 33 frameshift, 39 missense, 23 nonsense, 5 splicing, 4 deletion, and 1 translocation variants. Variation points are scattered throughout the gene, while exons 12, 15, and 10 were most common (25/105, 11/105, and 10/105, respectively). Some identical variants existing in different families could be hot variants, c.532A>T, p.(Asn178Tyr), c.1411C>T, p.(Gln471*), c.1608C>A, p.(Tyr536*), c.2026+1G>A, (splicing), and c.7276G>T, p.(Glu2426*). Short stature, early-onset osteoarthritis, brachydactyly, midfacial hypoplasia, and early growth cessation were the common phenotypic features. The 48 children who received rhGH (and GnRHa) treatment had a significant height improvement compared with before (-2.18 ± 1.06 SD vs. -2.69 ± 0.95 SD, p < 0.001). The heights of children who received rhGH (and GnRHa) treatment were significantly improved compared with those of untreated adults (-2.20 ± 1.10 SD vs. -3.24 ± 1.14 SD, p < 0.001). CONCLUSION Our study achieves a new understanding of the phenotypic spectrum, diagnosis, and management of individuals with ACAN variants. No clear genotype-phenotype relationship of patients with ACAN variants was found. Gene sequencing is necessary to diagnose ACAN variants that cause short stature. In general, appropriate rhGH and/or GnRHa therapy can improve the adult height of affected pediatric patients caused by ACAN variants.
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Affiliation(s)
- Wei Tang
- Department of PulmonaryChildren's Hospital of Zhejiang University School of MedicineHangzhouChina
| | - Ke‐Mi Wu
- Department of PulmonaryChildren's Hospital of Zhejiang University School of MedicineHangzhouChina
| | - Qiong Zhou
- Department of PulmonaryChildren's Hospital of Zhejiang University School of MedicineHangzhouChina
- Department of PediatricsHangzhou Children's HospitalHangzhouChina
| | - Yan‐Fei Tang
- Department of PulmonaryChildren's Hospital of Zhejiang University School of MedicineHangzhouChina
- Department of PediatricsJiaxing Second people's HospitalJiaxingChina
| | - Jun‐Fen Fu
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of MedicineHangzhouChina
| | - Guan‐Ping Dong
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of MedicineHangzhouChina
| | - Chao‐Chun Zou
- Department of EndocrinologyChildren's Hospital of Zhejiang University School of MedicineHangzhouChina
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Ahmed HA, Elhossini R, Aglan M, Amr K. Aggrecan-related bone disorders; a novel heterozygous ACAN variant associated with spondyloepimetaphyseal dysplasia expanding the phenotypic spectrum and review of literature. J Genet Eng Biotechnol 2024; 22:100341. [PMID: 38494255 PMCID: PMC10860877 DOI: 10.1016/j.jgeb.2023.100341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
BACKGROUND Spondyloepimetaphyseal dysplasias (SEMD) are a large group of skeletal disorders represented by abnormalities of vertebrae in addition to epiphyseal and metaphyseal areas of bones. Several genes have been identified underlying different forms. ACAN gene mutations were found to cause Aggrecan-related bone disorders (spondyloepimetaphyseal dysplasias,spondyloepiphyseal dysplasias, familial osteochondritis dissecans and short stature syndromes). This study aims to find the disease causing variant in Egyptian patient with SEMD using whole exome sequencing. METHODS Whole-exome sequencing was performed for an Egyptian male patient who presented with short stature, clinical and radiological features suggestive of unclassified SEMD. RESULTS The study identified a novel de novo heterozygous ACAN gene variant (c.7378G>A; p.Gly2460Arg) in G3 domain. Mutations in ACAN gene have been more commonly associated with short stature than SEMD. The phenotype of our patient was intermediate in severity between spondyloepiphyseal dysplasia presentation; Kimberley type(SEDK) and Spondyloepimetaphyseal dysplasias Aggrecan (SEMDAG) CONCLUSIONS: Whole exome sequencing revealed a novel de novo ACAN gene variant in patient with SEDK. The clinical and skeletal phenotype of our patient was much severe than those reported originally and showed more metaphyseal involvement. To the best of our knowledge, two previous studies reported a heterozygous variant in ACAN with spondyloepiphyseal dysplasia presentation; Kimberley type.
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Affiliation(s)
- Hoda A Ahmed
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Egypt.
| | - R Elhossini
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Egypt
| | - M Aglan
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Egypt
| | - Khalda Amr
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Egypt
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3
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Sao K, Risbud MV. Proteoglycan Dysfunction: A Common Link Between Intervertebral Disc Degeneration and Skeletal Dysplasia. Neurospine 2024; 21:162-178. [PMID: 38569642 PMCID: PMC10992626 DOI: 10.14245/ns.2347342.671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/04/2024] [Accepted: 02/23/2024] [Indexed: 04/05/2024] Open
Abstract
Proteoglycans through their sulfated glycosaminoglycans regulate cell-matrix signaling during tissue development, regeneration, and degeneration processes. Large extracellular proteoglycans such as aggrecan, versican, and perlecan are especially important for the structural integrity of the intervertebral disc and cartilage during development. In these tissues, proteoglycans are responsible for hydration, joint flexibility, and the absorption of mechanical loads. Loss or reduction of these molecules can lead to disc degeneration and skeletal dysplasia, evident from loss of disc height or defects in skeletal development respectively. In this review, we discuss the common proteoglycans found in the disc and cartilage and elaborate on various murine models and skeletal dysplasias in humans to highlight how their absence and/or aberrant expression causes accelerated disc degeneration and developmental defects.
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Affiliation(s)
- Kimheak Sao
- Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Makarand V. Risbud
- Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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4
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Saltarelli MA, Quarta A, Chiarelli F. Growth plate extracellular matrix defects and short stature in children. Ann Pediatr Endocrinol Metab 2022; 27:247-255. [PMID: 36567461 PMCID: PMC9816467 DOI: 10.6065/apem.2244120.060] [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: 05/16/2022] [Accepted: 06/29/2022] [Indexed: 12/27/2022] Open
Abstract
Many etiological factors causing short stature have already been identified in humans. In the last few years, the advent of new techniques for the detection of chromosomal and molecular abnormalities has made it possible to better identify patients with genetic causes of growth failure. Some of these factors directly affect the development and growth of the skeleton, since they damage the epiphyseal growth plate, where linear growth occurs, influencing chondrogenesis. In particular, defects in genes involved in the organization and function of the growth plate are responsible for several well-known conditions with short stature. These genes play a pivotal role in various mechanisms involving the extracellular matrix, intracellular signaling, paracrine signaling, endocrine signaling, and epigenetic regulation. In this review, we will discuss the genes involved in extracellular matrix disorders. The identification of genetic defects in linear growth failure is important for clinicians and researchers in order to improve the care of children affected by growth disorders.
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Affiliation(s)
| | - Alessia Quarta
- Department of Pediatrics, University of Chieti, Chieti, Italy
| | - Francesco Chiarelli
- Department of Pediatrics, University of Chieti, Chieti, Italy,Address for correspondence: Francesco Chiarelli Department of Pediatrics, University of Chieti, Via dei Vestini, 5 Chieti, I-66100, Italy
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5
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Kim TY, Jang KM, Keum CW, Oh SH, Chung WY. Identification of a heterozygous ACAN mutation in a 15-year-old boy with short stature who presented with advanced bone age: a case report and review of the literature. Ann Pediatr Endocrinol Metab 2020; 25:272-276. [PMID: 32871652 PMCID: PMC7788345 DOI: 10.6065/apem.1938198.099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 02/18/2020] [Indexed: 12/17/2022] Open
Abstract
Longitudinal bone growth is primarily mediated by the growth plate, which is a specialized cartilaginous structure. Aggrecan, encoded by ACAN, is a primary proteoglycan component of the extracellular matrix in both the growth plate and articular cartilage. Aggrecanopathies have emerged as a phenotype of genetic skeletal disease in humans. A heterozygous ACAN mutation causes short stature, premature growth cessation, and accelerated bone age maturation. We report the case of a 15-year-old boy with familial short stature, with height of 149 cm (Korean standard deviation score [SDS] of -3.6) and weight of 50.5 kg (-1.48 SDS). He presented with mild midfacial hypoplasia, frontal bossing, a broad chest, and a short neck. The father's and mother's heights were 150 cm (-4.8 SDS) and 153 cm (-1.69 SDS), respectively. The patient's bone age was 2-3 years more advanced than his chronological age, and no endocrine abnormalities were detected. Wholeexome sequencing followed by Sanger sequencing revealed a heterozygous ACAN mutation, c.512C>T (p.Ala171Val), in both the proband and his father. Short stature is generally associated with a delayed bone age, and this case suggests that ACAN mutations may be the most likely etiology among patients with short stature and an advanced bone age and should warrant early treatment.
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Affiliation(s)
- Tae Youp Kim
- Department of Pediatrics, Yeungnam University Hospital, Yeungnam University College of Medicine, Daegu, Korea
| | - Kyung Mi Jang
- Department of Pediatrics, Yeungnam University Hospital, Yeungnam University College of Medicine, Daegu, Korea,Address for co-correspondence: Kyung Mi Jang, MD, PhD Department of Pediatrics, Yeungnam Universit y Hospital, Yeungnam University College of Medicine, 170 Hyeonchung-ro, Nam-gu, Daegu 42415, Korea Tel: +82-53-620-3532 Fax: +82-53-629-2252 E-mail:
| | - Chang Won Keum
- Rare Genetic Disease Research Center, 3Billion Inc, Seoul, Korea
| | - Seung Hwan Oh
- Department of Laboratory Medicine, Inje University, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Woo Yeong Chung
- Department of Pediatrics, Inje University, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea,Address for correspondence: Woo Yeong Chung, MD, PhD Department of Pediatrics, Inje University Busan Paik Hospital, Inje University College of Medicine, 75 Bokji-ro, Busanjin-gu, Busan 47392, Korea Tel: +82-51-890-6280 Fax: +82-51-897-4012, E-mail:
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Krishnan Y, Grodzinsky AJ. Cartilage diseases. Matrix Biol 2018; 71-72:51-69. [PMID: 29803938 PMCID: PMC6146013 DOI: 10.1016/j.matbio.2018.05.005] [Citation(s) in RCA: 225] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 01/13/2023]
Abstract
Hyaline cartilages, fibrocartilages and elastic cartilages play multiple roles in the human body including bearing loads in articular joints and intervertebral discs, providing joint lubrication, forming the external ears and nose, supporting the trachea, and forming the long bones during development and growth. The structure and organization of cartilage's extracellular matrix (ECM) are the primary determinants of normal function. Most diseases involving cartilage lead to dramatic changes in the ECM which can govern disease progression (e.g., in osteoarthritis), cause the main symptoms of the disease (e.g., dwarfism caused by genetically inherited mutations) or occur as collateral damage in pathological processes occurring in other nearby tissues (e.g., osteochondritis dissecans and inflammatory arthropathies). Challenges associated with cartilage diseases include poor understanding of the etiology and pathogenesis, delayed diagnoses due to the aneural nature of the tissue and drug delivery challenges due to the avascular nature of adult cartilages. This narrative review provides an overview of the clinical and pathological features as well as current treatment options available for various cartilage diseases. Late breaking advances are also described in the quest for development and delivery of effective disease modifying drugs for cartilage diseases including osteoarthritis, the most common form of arthritis that affects hundreds of millions of people worldwide.
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Affiliation(s)
- Yamini Krishnan
- Department of Chemical Engineering, MIT, Cambridge, MA 02139, USA
| | - Alan J Grodzinsky
- Department of Biological Engineering, MIT, Cambridge, MA 02139, USA; Department of Mechanical Engineering, MIT, Cambridge, MA 02139, USA; Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA 02139, USA.
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Hauer NN, Sticht H, Boppudi S, Büttner C, Kraus C, Trautmann U, Zenker M, Zweier C, Wiesener A, Jamra RA, Wieczorek D, Kelkel J, Jung AM, Uebe S, Ekici AB, Rohrer T, Reis A, Dörr HG, Thiel CT. Genetic screening confirms heterozygous mutations in ACAN as a major cause of idiopathic short stature. Sci Rep 2017; 7:12225. [PMID: 28939912 PMCID: PMC5610314 DOI: 10.1038/s41598-017-12465-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/08/2017] [Indexed: 12/13/2022] Open
Abstract
Short stature is a common pediatric disorder affecting 3% of the population. However, the clinical variability and genetic heterogeneity prevents the identification of the underlying cause in about 80% of the patients. Recently, heterozygous mutations in the ACAN gene coding for the proteoglycan aggrecan, a main component of the cartilage matrix, were associated with idiopathic short stature. To ascertain the prevalence of ACAN mutations and broaden the phenotypic spectrum in patients with idiopathic short stature we performed sequence analyses in 428 families. We identified heterozygous nonsense mutations in four and potentially disease-causing missense variants in two families (1.4%). These patients presented with a mean of −3.2 SDS and some suggestive clinical characteristics. The results suggest heterozygous mutations in ACAN as a common cause of isolated as well as inherited idiopathic short stature.
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Affiliation(s)
- Nadine N Hauer
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Sangamitra Boppudi
- Institute of Human Genetics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Christian Büttner
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Cornelia Kraus
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Udo Trautmann
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Martin Zenker
- Institute of Human Genetics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Christiane Zweier
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Antje Wiesener
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, University of Leipzig, Leipzig, Germany
| | - Dagmar Wieczorek
- Institute of Human Genetics, University of Duisburg-Essen, Essen, Germany.,Institute of Human-Genetics, Medical Faculty, Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Jaqueline Kelkel
- Division of Pediatric Endocrinology, Department of Pediatrics and Neonatology, Saarland University Hospital, Homburg/Saar, Germany
| | - Anna-Maria Jung
- Division of Pediatric Endocrinology, Department of Pediatrics and Neonatology, Saarland University Hospital, Homburg/Saar, Germany
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Tilman Rohrer
- Division of Pediatric Endocrinology, Department of Pediatrics and Neonatology, Saarland University Hospital, Homburg/Saar, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Helmuth-Günther Dörr
- Department of Pediatrics and Adolescent Medicine, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Christian T Thiel
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
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Tatsi C, Gkourogianni A, Mohnike K, DeArment D, Witchel S, Andrade AC, Markello TC, Baron J, Nilsson O, Jee YH. Aggrecan Mutations in Nonfamilial Short Stature and Short Stature Without Accelerated Skeletal Maturation. J Endocr Soc 2017; 1:1006-1011. [PMID: 29264551 PMCID: PMC5686699 DOI: 10.1210/js.2017-00229] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/23/2017] [Indexed: 02/07/2023] Open
Abstract
Aggrecan, a proteoglycan, is an important component of cartilage extracellular matrix, including that of the growth plate. Heterozygous mutations in ACAN, the gene encoding aggrecan, cause autosomal dominant short stature, accelerated skeletal maturation, and joint disease. The inheritance pattern and the presence of bone age equal to or greater than chronological age have been consistent features, serving as diagnostic clues. From family 1, a 6-year-old boy presented with short stature [height standard deviation score (SDS), -1.75] and bone age advanced by 3 years. There was no family history of short stature (height SDS: father, -0.76; mother, 0.7). Exome sequencing followed by Sanger sequencing identified a de novo novel heterozygous frameshift mutation in ACAN (c.6404delC: p.A2135Dfs). From family 2, a 12-year-old boy was evaluated for short stature (height SDS, -3.9). His bone age at the time of genetic evaluation was approximately 1 year less than his chronological age. Family history was consistent with an autosomal dominant inheritance of short stature, with several affected members also showing early-onset osteoarthritis. Exome sequencing, confirmed by Sanger sequencing, identified a novel nonsense mutation in ACAN (c.4852C>T: p.Q1618X), which cosegregated with the phenotype. In conclusion, patients with ACAN mutations may present with nonfamilial short stature and with bone age less than chronological age. These findings expand the known phenotypic spectrum of heterozygous ACAN mutations and indicate that this diagnosis should be considered in children without a family history of short stature and in children without accelerated skeletal maturation.
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Affiliation(s)
- Christina Tatsi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland 20892
| | - Alexandra Gkourogianni
- Karolinska Institutet, Department of Women's and Children's Health, SE-171 77 Stockholm, Sweden
| | - Klaus Mohnike
- Department of Pediatrics, Otto-von-Guericke-University, 39104 Magdeburg, Germany
| | - Diana DeArment
- Division of Pediatric Endocrinology, Children's Hospital of Pittsburgh of University of Pittsburg Medical Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15224
| | - Selma Witchel
- Division of Pediatric Endocrinology, Children's Hospital of Pittsburgh of University of Pittsburg Medical Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15224
| | - Anenisia C. Andrade
- Karolinska Institutet, Department of Women's and Children's Health, SE-171 77 Stockholm, Sweden
| | - Thomas C. Markello
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Jeffrey Baron
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland 20892
| | - Ola Nilsson
- Karolinska Institutet, Department of Women's and Children's Health, SE-171 77 Stockholm, Sweden
- Department of Medical Sciences, Örebro University, 702 03 Örebro, Sweden
| | - Youn Hee Jee
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland 20892
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Dateki S. ACAN mutations as a cause of familial short stature. Clin Pediatr Endocrinol 2017; 26:119-125. [PMID: 28804204 PMCID: PMC5537209 DOI: 10.1297/cpe.26.119] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 03/25/2017] [Indexed: 12/18/2022] Open
Abstract
Aggrecan, encoded by ACAN, is a major proteoglycan component of the
extracellular matrix in the growth plate and articular cartilage. Aggrecan provides the
hydrated gel structure important for the load-bearing properties of joints and plays a key
role in cartilage and bone morphogenesis. At least 25 pathological ACAN
mutations have been identified in patients with highly variable phenotypes of syndromic or
non-syndromic short stature. This review provides an overview of the current understanding
of ACAN and the clinical and genetic findings concerning
aggrecan-associated diseases.
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Affiliation(s)
- Sumito Dateki
- Department of Pediatrics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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10
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van der Steen M, Pfundt R, Maas SJWH, Bakker-van Waarde WM, Odink RJ, Hokken-Koelega ACS. ACAN Gene Mutations in Short Children Born SGA and Response to Growth Hormone Treatment. J Clin Endocrinol Metab 2017; 102:1458-1467. [PMID: 27710243 DOI: 10.1210/jc.2016-2941] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/03/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Some children born small for gestational age (SGA) show advanced bone age (BA) maturation during growth hormone (GH) treatment. ACAN gene mutations have been described in children with short stature and advanced BA. OBJECTIVE To determine the presence of ACAN gene mutations in short SGA children with advanced BA and assess the response to GH treatment. METHODS BA assessment in 290 GH-treated SGA children. ACAN sequencing in 29 children with advanced BA ≥0.5 years compared with calendar age. RESULTS Four of 29 SGA children with advanced BA had an ACAN gene mutation (13.8%). Mutations were related to additional characteristics: midface hypoplasia (P = 0.003), joint problems (P = 0.010), and broad great toes (P = 0.003). Children with one or fewer additional characteristic had no mutation. Of children with two additional characteristics, 50% had a mutation. Of children with three additional characteristics, 100% had a mutation. All GH-treated children with a mutation received gonadotropin-releasing hormone analog (GnRHa) treatment for 2 years from onset of puberty. At adult height, one girl was 5 cm taller than her mother and one boy was 8 cm taller than his father with the same ACAN gene mutation. CONCLUSION This study expands the differential diagnosis of genetic variants in children born SGA and proposes a clinical scoring system for identifying subjects most likely to have an ACAN gene mutation. ACAN sequencing should be considered in children born SGA with persistent short stature, advanced BA, and midface hypoplasia, joint problems, or broad great toes. Our findings suggest that children with an ACAN gene mutation benefit from GH treatment with 2 years of GnRHa.
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Affiliation(s)
- Manouk van der Steen
- Dutch Growth Research Foundation, 3001 KB Rotterdam, The Netherlands
- Erasmus University Medical Center-Sophia Children's Hospital, 3015 GJ Rotterdam, The Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Division of Genome Diagnostics, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen, The Netherlands
| | - Stephan J W H Maas
- Department of Human Genetics, Division of Genome Diagnostics, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen, The Netherlands
| | - Willie M Bakker-van Waarde
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Roelof J Odink
- Department of Pediatrics, Catharina Hospital, 5623 EJ Eindhoven, The Netherlands
| | - Anita C S Hokken-Koelega
- Dutch Growth Research Foundation, 3001 KB Rotterdam, The Netherlands
- Erasmus University Medical Center-Sophia Children's Hospital, 3015 GJ Rotterdam, The Netherlands
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Gibson BG, Briggs MD. The aggrecanopathies; an evolving phenotypic spectrum of human genetic skeletal diseases. Orphanet J Rare Dis 2016; 11:86. [PMID: 27353333 PMCID: PMC4924316 DOI: 10.1186/s13023-016-0459-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 05/27/2016] [Indexed: 12/25/2022] Open
Abstract
The large chondroitin sulphated proteoglycan aggrecan (ACAN) is the most abundant non-collagenous protein in cartilage and is essential for its structure and function. Mutations in ACAN result in a broad phenotypic spectrum of non-lethal skeletal dysplasias including spondyloepimetaphyseal dysplasia, spondyloepiphyseal dysplasia, familial osteochondritis dissecans and various undefined short stature syndromes associated with accelerated bone maturation. However, very little is currently known about the disease pathways that underlie these aggrecanopathies, although they are likely to be a combination of haploinsufficiency and dominant-negative (neomorphic) mechanisms. This review discusses the known human and animal aggrecanopathies in the context of clinical presentation and potential disease mechanisms.
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Affiliation(s)
- Beth G Gibson
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, NE1 3BZ, UK
| | - Michael D Briggs
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, NE1 3BZ, UK. .,International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK.
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Quintos JB, Guo MH, Dauber A. Idiopathic short stature due to novel heterozygous mutation of the aggrecan gene. J Pediatr Endocrinol Metab 2015; 28:927-32. [PMID: 25741789 PMCID: PMC4501863 DOI: 10.1515/jpem-2014-0450] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/29/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND Recently, whole exome sequencing identified heterozygous defects in the aggrecan (ACAN) gene in three families with short stature and advanced bone age. OBJECTIVE We report a novel frameshift mutation in ACAN in a family with dominantly inherited short stature, advanced bone age, and premature growth cessation. This is the first case of targeted sequencing of ACAN in this phenotype and confirms that ACAN sequencing is warranted in patients with this rare constellation of findings. RESULTS We present a 5 1/2-year-old male with a family history of short stature in three generations. The maternal grandfather stands 144.5 cm (Ht SDS -4.7), mother 147.7 cm (Ht SDS -2.6), and index case 99.2 cm (Ht SDS -2.7). Our prepubertal patient has significant bone age advancement (bone age 8 years at chronologic age 5 1/2 years) resulting in a poor predicted adult height of 142 cm (Ht SDS -5.1). DNA sequencing identified a novel heterozygous variant in ACAN, which encodes aggrecan, a proteoglycan in the extracellular matrix of growth plate and other cartilaginous tissues. The mutation (p.Gly1797Glyfs*52) results in premature truncation and presumed loss of protein function. CONCLUSION Mutations in the ACAN gene should be included in the differential diagnosis of the child with idiopathic short stature or familial short stature and bone age advancement.
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Affiliation(s)
- Jose Bernardo Quintos
- Rhode Island Hospital/Hasbro Children's Hospital-The Warren Alpert Medical School of Brown University, Division of Pediatric Endocrinology, 593 Eddy St, MPS2, Providence, RI 02903
| | - Michael H. Guo
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115
| | - Andrew Dauber
- Division of Endocrinology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229
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Kurt S, Kartal E, Aksoy D, Cevik B, Eken AG, Sahbaz I, Nazli Basak A. Coexistence of autosomal recessive spastic ataxia of Charlevoix Saguenay and spondyloepiphyseal dysplasia in a Turkish patient. J Neurol Sci 2015; 357:290-1. [PMID: 26142023 DOI: 10.1016/j.jns.2015.06.050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 06/22/2015] [Accepted: 06/23/2015] [Indexed: 12/22/2022]
Affiliation(s)
- Semiha Kurt
- Gaziosmanpasa University, Faculty of Medicine, Department of Neurology, Tokat, Turkey.
| | - Ece Kartal
- Bogazici University, Molecular Biology and Genetics Department, Suna and Inan Kıraç Foundation Neurodegeneration Research Laboratory, Istanbul, Turkey
| | - Durdane Aksoy
- Gaziosmanpasa University, Faculty of Medicine, Department of Neurology, Tokat, Turkey
| | - Betul Cevik
- Gaziosmanpasa University, Faculty of Medicine, Department of Neurology, Tokat, Turkey
| | - Asli Gundogdu Eken
- Bogazici University, Molecular Biology and Genetics Department, Suna and Inan Kıraç Foundation Neurodegeneration Research Laboratory, Istanbul, Turkey
| | - Irmak Sahbaz
- Bogazici University, Molecular Biology and Genetics Department, Suna and Inan Kıraç Foundation Neurodegeneration Research Laboratory, Istanbul, Turkey
| | - A Nazli Basak
- Bogazici University, Molecular Biology and Genetics Department, Suna and Inan Kıraç Foundation Neurodegeneration Research Laboratory, Istanbul, Turkey
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Nilsson O, Guo MH, Dunbar N, Popovic J, Flynn D, Jacobsen C, Lui JC, Hirschhorn JN, Baron J, Dauber A. Short stature, accelerated bone maturation, and early growth cessation due to heterozygous aggrecan mutations. J Clin Endocrinol Metab 2014; 99:E1510-8. [PMID: 24762113 PMCID: PMC4121031 DOI: 10.1210/jc.2014-1332] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CONTEXT Many children with idiopathic short stature have a delayed bone age. Idiopathic short stature with advanced bone age is far less common. OBJECTIVE The aim was to identify underlying genetic causes of short stature with advanced bone age. SETTING AND DESIGN We used whole-exome sequencing to study three families with autosomal-dominant short stature, advanced bone age, and premature growth cessation. RESULTS Affected individuals presented with short stature [adult heights -2.3 to -4.2 standard deviation scores (SDS)] with histories of early growth cessation or childhood short stature (height SDS -1.9 to -3.5 SDS), advancement of bone age, and normal endocrine evaluations. Whole-exome sequencing identified novel heterozygous variants in ACAN, which encodes aggrecan, a proteoglycan in the extracellular matrix of growth plate and other cartilaginous tissues. The variants were present in all affected, but in no unaffected, family members. In Family 1, a novel frameshift mutation in exon 3 (c.272delA) was identified, which is predicted to cause early truncation of the aggrecan protein. In Family 2, a base-pair substitution was found in a highly conserved location within a splice donor site (c.2026+1G>A), which is also likely to alter the amino acid sequence of a large portion of the protein. In Family 3, a missense variant (c.7064T>C) in exon 14 affects a highly conserved residue (L2355P) and is strongly predicted to perturb protein function. CONCLUSIONS Our study demonstrates that heterozygous mutations in ACAN can cause a mild skeletal dysplasia, which presents clinically as short stature with advanced bone age. The accelerating effect on skeletal maturation has not previously been noted in the few prior reports of human ACAN mutations. Our findings thus expand the spectrum of ACAN defects and provide a new molecular genetic etiology for the unusual child who presents with short stature and accelerated skeletal maturation.
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Affiliation(s)
- Ola Nilsson
- Program in Developmental Endocrinology and Genetics (O.N., J.C.L., J.B.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892; Center for Molecular Medicine and Pediatric Endocrinology Unit, Department of Women's and Children's Health (O.N.), Karolinska Institutet and Karolinska University Hospital, SE-171 76 Stockholm, Sweden; Program in Biological and Biomedical Sciences (M.H.G.), Harvard Medical School, Boston, Massachusetts 02115; Connecticut Children's Medical Center (N.D.), Hartford, Connecticut 06106; Children's Hospital of Pittsburgh (J.P., D.F.), University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15224; Division of Endocrinology (M.H.G., C.J., J.N.H., A.D.), Boston Children's Hospital, Boston, Massachusetts 02115; Department of Genetics (M.H.G., J.N.H.), Harvard Medical School, Boston, Massachusetts 02115; and Program in Medical and Population Genetics (J.N.H., A.D.), Broad Institute, Cambridge, Massachusetts 02142
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Abstract
Height is a complex genetic trait that involves multiple genetic loci. Recently, 44 loci associated with height were identified in Caucasian individuals by large-scale genome-wide association (GWA) studies. To identify genetic variants influencing height in the Korean population, we analyzed GWA data from 8842 Korean individuals and identified 15 genomic regions with one or more sequence variants associated with height (P<1 x 10(-5)). Of these, eight loci were newly identified in Koreans (SUPT3H, EXT1, FREM1, PALM2-AKAP2, NUP37-PMCH, IGF1, KRT20 and ANKRD60). The 15 significant loci account for approximately 1.0% of height variation, with a 3.7-cm difference between individuals with < or =8 height-increasing alleles (5.1%) and > or =19 height-increasing alleles (4.2%). We also examined the associations between height loci and idiopathic short stature (ISS). Five loci (SPAG17, KBTBD8, HHIP, HIST1H1D and ACAN) were significantly associated with ISS (uncorrected P<0.05), indicating that height-associated genes in the adult population are involved in extreme cases of short stature in children. This study validates previous reports of loci associated with human height and identified novel candidate regions involved in human growth and development.
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16
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Gleghorn L, Ramesar R, Beighton P, Wallis G. A mutation in the variable repeat region of the aggrecan gene (AGC1) causes a form of spondyloepiphyseal dysplasia associated with severe, premature osteoarthritis. Am J Hum Genet 2005; 77:484-90. [PMID: 16080123 PMCID: PMC1226213 DOI: 10.1086/444401] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 06/27/2005] [Indexed: 02/05/2023] Open
Abstract
Spondyloepiphyseal dysplasia (SED) encompasses a heterogeneous group of disorders characterized by shortening of the trunk and limbs. The autosomal dominant SED type Kimberley (SEDK) is associated with premature degenerative arthropathy and has been previously mapped in a multigenerational family to a novel locus on 15q26.1. This locus contains the gene AGC1, which encodes aggrecan, the core protein of the most abundant proteoglycan of cartilage. We screened AGC1 for mutations and identified a single-base-pair insertion, within the variable repeat region of exon 12 in affected individuals from the family with SEDK, that introduces a frameshift of 212 amino acids, including 22 cysteine residues, followed by a premature stop codon. This is the first identification of an AGC1 mutation causing a human disorder. This finding extends the spectrum of mutated genes that may cause SED and thus will aid in the molecular delineation of this complex group of conditions.
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Affiliation(s)
- Lindsay Gleghorn
- The Wellcome Trust Centre for Cell-Matrix Research, The University of Manchester, Manchester, United Kingdom
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17
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Abstract
In contrast to late-onset osteoarthritis (OA), the appearance of precocious OA has historically been recognized as a particularly aggressive form of the disorder that is frequently inherited as a Mendelian trait. In general, precocious OA appears as a consequence of many skeletal dysplasias, which, although individually rare, comprise a sizable population of patients when viewed in toto. In these patients the disease is often rapidly progressive and includes features of articular and extra-articular involvement that are not typical of classic OA. The molecular pathology of the chondro-osseous disorders has been the focus of intense study in recent years, with the promise of providing insight into skeletal development and homeostasis, as well as the aetiology and pathogenesis of degenerative joint disease.
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Affiliation(s)
- Charlene J Williams
- Department of Medicine, Division of Rheumatology, Thomas Jefferson University, 233 S. 10th Street Room 509 BLSB, Philadelphia, PA 19107, USA
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18
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Donahue LR, Chang B, Mohan S, Miyakoshi N, Wergedal JE, Baylink DJ, Hawes NL, Rosen CJ, Ward-Bailey P, Zheng QY, Bronson RT, Johnson KR, Davisson MT. A missense mutation in the mouse Col2a1 gene causes spondyloepiphyseal dysplasia congenita, hearing loss, and retinoschisis. J Bone Miner Res 2003; 18:1612-21. [PMID: 12968670 PMCID: PMC2862909 DOI: 10.1359/jbmr.2003.18.9.1612] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED A missense mutation in the mouse Col2a1 gene has been discovered, resulting in a mouse phenotype with similarities to human spondyloepiphyseal dysplasia (SED) congenita. In addition, SED patients have been identified with a similar molecular mutation in human COL2A1. This mouse model offers a useful tool for molecular and biological studies of bone development and pathology. INTRODUCTION A new mouse autosomal recessive mutation has been discovered and named spondyloepiphyseal dysplasia congenita (gene symbol sedc). MATERIALS AND METHODS Homozygous sedc mice can be identified at birth by their small size and shortened trunk. Adults have shortened noses, dysplastic vertebrae, femora, and tibias, plus retinoschisis and hearing loss. The mutation was mapped to Chr15, and Col2a1 was identified as a candidate gene. RESULTS Sequence analyses revealed that the affected gene is Col2a1, which has a missense mutation at exon 48 causing an amino acid change of arginine to cysteine at position 1417. Two human patients with spondyloepiphyseal dysplasia (SED) congenita have been reported with the same amino acid substitution at position 789 in the human COL2A1 gene. CONCLUSIONS Thus, sedc/sedc mice provide a valuable model of human SED congenita with molecular and phenotypic homology. Further biochemical analyses, molecular modeling, and cell culture studies using sedc/sedc mice could provide insight into mechanisms of skeletal development dependent on Col2a1 and its role in fibril formation and cartilage template organization.
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19
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Eyre S, Roby P, Wolstencroft K, Spreckley K, Aspinwall R, Bayoumi R, Al-Gazali L, Ramesar R, Beighton P, Wallis G. Identification of a locus for a form of spondyloepiphyseal dysplasia on chromosome 15q26.1: exclusion of aggrecan as a candidate gene. J Med Genet 2002; 39:634-8. [PMID: 12205105 PMCID: PMC1735219 DOI: 10.1136/jmg.39.9.634] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have investigated a family with an autosomal dominant form of spondyloepiphyseal dysplasia (SED) characterised by short stature and severe premature degenerative arthropathy. Previous studies have excluded linkage between this condition and the locus for the type II collagen gene. Here we report the identification of linkage between this disorder and a locus on the long arm of chromosome 15 between markers D15S979 and D15S1004. According to current linkage maps and sequence data, this locus includes that of the aggrecan gene (AGC1). Our linkage data from the SED family show, however, that AGC1 maps to a locus that is proximal to D15S979. This proximal location for AGC1 is further supported by linkage data from a second family with an autosomal recessive form of multiple epiphyseal dysplasia that also maps to the SED locus. In both families AGC1 is therefore excluded as a candidate gene.
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Affiliation(s)
- S Eyre
- The Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, UK
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20
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International nomenclature and classification of the osteochondrodysplasias (1997). International Working Group on Constitutional Diseases of Bone. AMERICAN JOURNAL OF MEDICAL GENETICS 1998; 79:376-82. [PMID: 9779805 DOI: 10.1002/(sici)1096-8628(19981012)79:5<376::aid-ajmg9>3.0.co;2-h] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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Beighton P, Cilliers HJ, Ramesar R. Autosomal dominant (Beukes) premature degenerative osteoarthropathy of the hip joint unlinked to COL2A1. AMERICAN JOURNAL OF MEDICAL GENETICS 1994; 53:348-51. [PMID: 7864044 DOI: 10.1002/ajmg.1320530408] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Molecular investigations have been undertaken in several separate large South African families with autosomal dominant skeletal dysplasias in which premature degenerative osteoarthropathy of the hip joint was the major manifestation. There are sometimes additional minor changes in the spine and these conditions fall into the general spondyloepiphyseal dysplasia (SED) nosological category. In some kindreds, linkage between phenotype and the type II collagen gene (COL2A1) has been established, while in others there is no linkage. We have now completed molecular linkage investigations in an Afrikaner family named Beukes, in which 47 members in 6 generations have premature osteoarthropathy of the hip joint. A LOD score of minus infinity indicates that this condition is not the result of a defect of the COL2A1 gene.
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Affiliation(s)
- P Beighton
- Department of Human Genetics, University of Cape Town, Medical School, Republic of South Africa
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22
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Abstract
Cartilage diseases include a wide variety of clinical phenotypes from common osteoarthrosis to several different types of chondrodysplasias, i.e. 'disorders of cartilage', of which more than 100 different have been described. Patients frequently suffer from various symptoms affecting their joints and/or the growth of their long bones. The amount of hyaline cartilage at articular surfaces is often diminished and structurally abnormal. The surface of the cartilage may have an irregular appearance with defects extending into the subchondral bone. The major constituents of this hyaline cartilage are collagens and proteoglycans, the most abundant protein being type II collagen. It is a homotrimer of three identical alpha-chains, which are encoded by a single gene on human chromosome 12. The gene for type II collagen therefore became a likely candidate for some forms of chondrodysplasias and cartilage degeneration. Recently, both linkages and exclusions between this gene and various cartilage diseases have been reported and a growing number of mutations within the gene have also been identified.
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Affiliation(s)
- M Vikkula
- Department of Human Molecular Genetics, National Public Health Institute, Helsinki, Finland
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23
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Abstract
The molecular basis for several hereditary disorders of connective tissues has been elucidated in recent years. In this chapter, we discuss recent advances in the molecular characterization of a number of these disorders and examine their clinical applications.
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Affiliation(s)
- D J Tilstra
- Department of Pathology, University of Washington, Seattle 98195
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24
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Abstract
With the application of molecular techniques the aetiopathogenesis of skeletal dysplasias is gradually elucidated. Recent advances show that some bone dysplasias result from defects in the biosynthesis of type II (cartilage) collagen. Clinical entities caused by mutations in the COL2A1 gene coding for type II collagen comprise achondrogenesis II, hypochondrogenesis, spondyloepiphyseal dysplasia congenita, Kniest dysplasia, Stickler arthroophthalmopathy and mild dominant spondyloarthropathy. The mutations are expressed in the heterozygous state, and inheritance of type II collagenopathies is autosomal dominant. The wide range of clinical manifestations is not well understood but characterization of the basic defect may provide clues to establish specific genotype-phenotype correlations.
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Affiliation(s)
- J Spranger
- Universitäts-Kinderklinik, Mainz, Germany
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25
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Bonaventure J, Stanescu R, Stanescu V, Allain JC, Muriel MP, Ginisty D, Maroteaux P. Type II collagen defect in two sibs with the Goldblatt syndrome, a chondrodysplasia with dentinogenesis imperfecta, and joint laxity. AMERICAN JOURNAL OF MEDICAL GENETICS 1992; 44:738-53. [PMID: 1481841 DOI: 10.1002/ajmg.1320440607] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report on a syndrome of spondylo-epimetaphyseal dysplasia, dentinogenesis imperfecta, and ligamentous hyperextensibility in two sibs born to nonconsanguineous parents. This chondrodysplasia was characterized by severe shortness of stature and an osteoporosis without fractures. Electron microscopic examination of the cartilage documented large vacuoles of dilated rough endoplasmic reticulum within the cytoplasm of chondrocytes. Gel electrophoresis of pepsin-soluble collagen extracted from cartilage demonstrated the presence of type II collagen chains with an abnormal mobility. Prolyl and lysyl hydroxylations were slightly increased. The abnormal molecules melted at a higher temperature than the normal ones. CNBr peptide mapping of type II collagen showed an altered electrophoretic migration of peptides CB 11, CB 8, and CB 10,5 whereas CB 9,7 looked normal. In addition, two small non-collagenous proteins isolated from cartilage were not found in an age-matched control individual but were detected in a normal newborn infant. The quantitation of proline-labelled collagen synthesized by dermal fibroblasts demonstrated a 50% reduction of total collagen. This decrease essentially affected the amount of extracellular type I collagen, which was secreted less efficiently than in control cells. Nevertheless, type I collagen chains behaved normally on 5% polyacrylamide gels. The reduced mRNA levels of alpha 1I and alpha 2I chains might reflect either a transcriptional defect or a decreased stability of mRNA transcripts. We suggest that the association of both pathological chondrocytes producing altered collagen type II and decreased synthesis of type I could be responsible for this peculiar phenotype. The overmodification of alpha 1II CNBr peptides is consistent with the presence of a single-base substitution in the COL2A1 gene. Whether there is a direct causal relationship between the type II collagen defect and the underexpression of type I collagen will require clarification.
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Affiliation(s)
- J Bonaventure
- Clinique Maurice Lamy, Hôpital des Enfants Malades, Paris, France
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26
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Ramesar R, Beighton P. Spondyloepiphyseal dysplasia in a Cape Town family: linkage with the gene for type II collagen (COL2A1). ACTA ACUST UNITED AC 1992; 43:833-8. [PMID: 1353665 DOI: 10.1002/ajmg.1320430516] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A moderately severe form of autosomal dominant (AD) spondyloepiphyseal dysplasia (SED) has been documented in 14 individuals in 3 generations of a family in Cape Town, South Africa. Affected persons had a short trunk; radiographic investigations indicated that skeletal involvement was worst in the hips and spine. Linkage studies with restriction fragment length polymorphisms (RFLPs) associated with the COL2A1 gene and the phenotype yielded a maximal LOD score of 4.51 at theta = 0.00. This result suggests that the structural locus for type II collagen is primarily involved in the pathogenesis of this form of SED.
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Affiliation(s)
- R Ramesar
- Department of Human Genetics, Medical School, University of Cape Town, South Africa
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Beighton P, De Paepe A, Hall JG, Hollister DW, Pope FM, Pyeritz RE, Steinmann B, Tsipouras P. Molecular nosology of heritable disorders of connective tissue. AMERICAN JOURNAL OF MEDICAL GENETICS 1992; 42:431-48. [PMID: 1609825 DOI: 10.1002/ajmg.1320420406] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- P Beighton
- Department of Human Genetics, Medical School, University of Cape Town, South Africa
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28
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Spranger J. Classification of skeletal dysplasias. ACTA PAEDIATRICA SCANDINAVICA. SUPPLEMENT 1991; 377:138-42. [PMID: 1785308 DOI: 10.1111/apa.1991.80.s377.138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- J Spranger
- Children's Hospital, University of Mainz, Germany
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29
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Viljoen D, Ramesar R, Behari D. Beals syndrome: clinical and molecular investigations in a kindred of Indian descent. Clin Genet 1991; 39:181-8. [PMID: 1674682 DOI: 10.1111/j.1399-0004.1991.tb03009.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Eight members of a 3-generation kindred of Indian descent with congenital contractural arachnodactyly (Beals syndrome) have been appraised. Considerable variation was noted in the clinical features of affected persons, and the previously unreported associated finding of clubbing of the fingers and toes was evident in two individuals. The family was investigated using conventional serum and protein markers, and RFLP probes for type I and II collagen. No linkage in affected members could be demonstrated with type I collagen probes.
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Affiliation(s)
- D Viljoen
- Department of Human Genetics, University of Cape Town, Medical School, Observatory, South Africa
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