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Amajjar I, Vergauwen K, Willigenburg NW, Ham SJ, Smeets RJEM. Pain and fatigue in adult patients with multiple osteochondromas: The Netherlands. PLoS One 2024; 19:e0305640. [PMID: 39018287 PMCID: PMC11253920 DOI: 10.1371/journal.pone.0305640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 06/03/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND Multiple Osteochondromas (MO) is a rare genetic disorder characterised by the presence of numerous benign bone tumours, known as osteochondromas. Within the spectrum of debilitating symptoms associated with MO, pain is recognized as a major problem. Interestingly, our clinical observations suggest that fatigue is also a significant concern but has merely been touched upon in MO literature. This study aims to (1) assess the level of pain and fatigue in adult patients with MO; (2) compare fatigue in MO to healthy subjects and patients with Rheumatoid Arthritis (RA); (3) identify associated variables for pain and fatigue in patients with MO. METHODS In this cross-sectional study, 353 adult MO patients completed a survey with validated questionnaires on pain, fatigue and psychosocial factors. Pain and fatigue were assessed with the Numeric Rating Scale (NRS), and fatigue was also measured with the Checklist Individual Strength (CIS). Fatigue (CIS) was compared with reference scores of healthy subjects and patients with RA, using a one-sample t-test. Multiple linear regression models for pain and fatigue were developed using a-priori selected independent variables based on a theoretical framework (ICF-model). RESULTS Pain was reported by 87.8% (NRS = 3.19±2.6) and fatigue by 90.4% (NRS = 4.1±2.6) of patients with MO. Fatigue scores for MO (CIS = 84.1±15.3) were significantly higher (p<0.001) compared to reference scores of healthy subjects and patients with RA. The multivariable analysis for pain provided a final regression model with six variables (R2 = 0.445, p<0.001) of which fear avoidance beliefs and fatigue had the strongest association. For the fatigue models NRS (R2 = 0.455, p<0.001) and CIS (R2 = 0.233, p<0.001), the strongest associations were found with anxiety and depression respectively. CONCLUSIONS Pain and fatigue are highly prevalent in patients with MO. Fatigue is significantly higher compared to healthy subjects and patients with RA. Several variables associated with pain and fatigue have been identified that could help improve multidisciplinary treatment plans.
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Affiliation(s)
- Ihsane Amajjar
- Department of Orthopaedic Surgery, OLVG, Amsterdam, The Netherlands
- Department of Rehabilitation Medicine, CAPHRI, Maastricht University, Maastricht, The Netherlands
| | - Kuni Vergauwen
- Department of Rehabilitation Medicine, CAPHRI, Maastricht University, Maastricht, The Netherlands
- Department of Health Care, AP University College, Antwerp, Belgium
- MOVANT, Department of Rehabilitation Sciences and Physiotherapy, University of Antwerp, Antwerp, Belgium
- Pain in Motion International Research Group, Brussels, Belgium
| | | | - S. John Ham
- Department of Orthopaedic Surgery, OLVG, Amsterdam, The Netherlands
| | - Rob J. E. M. Smeets
- Department of Health Care, AP University College, Antwerp, Belgium
- Pain in Motion International Research Group, Brussels, Belgium
- Clinics in Rehabilitation, Eindhoven, The Netherlands
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A Genotype-Phenotype Study of Multiple Hereditary Exostoses in Forty-Three Patients. J Clin Med 2022; 11:jcm11133703. [PMID: 35806987 PMCID: PMC9267182 DOI: 10.3390/jcm11133703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/21/2022] [Accepted: 06/21/2022] [Indexed: 12/03/2022] Open
Abstract
Multiple hereditary exostoses (MHE) is a rare autosomal dominant skeletal disorder with a variety of clinical manifestations. We aimed to evaluate the general clinical phenotypic severity of MHE using our own scoring system and analyzed the risk factors associated with severe clinical phenotypes. In this study, 43 patients from 30 families were analyzed. The mutations were identified by direct sequencing of polymerase chain reaction-amplified genomic DNA or by multiplex ligation-dependent probe amplification. According to a new scoring system devised by the authors, the severity of the phenotype was assessed as mild, moderate, or severe based on the deformity of each segment, number of exostoses, leg length discrepancy, and functional limitations. Of 43 patients from 30 families, 39 patients (90.7%) and 24 families (80%) presented with EXT1 or EXT2 mutations. Patients with EXT1 mutations had a significantly worse phenotype than that of patients with EXT2 mutations or without any detectable mutation. The mean clinical score of patients with an EXT1 mutation (5.76; range, 2.0–8.0; SD = 1.60) was higher than that of patients with an EXT2 mutation (4.06; range, 2.0–7.0; SD = 1.47) or of those without any detectable mutation (4.63; range, 3.0–6.0; SD = 1.44; p = 0.005). According to our classification system, more patients with EXT1 mutations had ‘severe disease’ than those with EXT2 mutations. Deformity scores were also higher in patients with EXT1 mutations (p = 0.018). In the multivariate analysis, the deformity score was found to be associated with the ‘severe’ class (p = 0.031). In conclusion, 90.7% of patients with MHE showed EXT mutations. Our scoring system showed reliable results. We suggest that the extent of deformity is an important factor in determining the phenotype of MHE and close monitoring for the development of severe disease is recommended in patients with high deformity scores.
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Fujii Y, Uno A, Takitani S, Iwasaki R, Yoshikawa R, Okajima M, Makino Y, Ito N, Mori T. A frameshift variant in the EXT1 gene in a feline leukemia virus-negative cat with osteochondromatosis. Anim Genet 2022; 53:696-699. [PMID: 35719100 DOI: 10.1111/age.13232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/15/2022] [Accepted: 06/07/2022] [Indexed: 11/30/2022]
Abstract
Osteochondromatosis is a benign proliferative disorder characterized by cartilage-capped bony protuberances. In humans and most mammals, variants in the EXT1 or EXT2 gene are strongly correlated with the etiology of osteochondromatosis. However, in cats, osteochondromatosis has only been associated with feline leukemia virus infection. In this study, to explore other factors involved in the etiology of feline osteochondromatosis, we examined the EXT1 and EXT2 genes in a feline leukemia virus-negative cat with osteochondromatosis. Genetic analysis revealed a heterozygous single base pair duplication in exon 6 of the EXT1 gene (XM_023248762.2:c.1468dupC), leading to a premature stop codon in the EXT1 protein. Notably, this frameshift variant is recognized as one of the most common pathogenic variants in human osteochondromatosis. Our data suggest for the first time that genetic variants can have etiologic roles in osteochondromatosis in cats, as in humans and other animals.
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Affiliation(s)
- Yuji Fujii
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu, Japan.,Animal Medical Center, Gifu University, Gifu, Gifu, Japan
| | - Akihiro Uno
- Animal Medical Center, Gifu University, Gifu, Gifu, Japan
| | | | - Ryota Iwasaki
- Animal Medical Center, Gifu University, Gifu, Gifu, Japan
| | | | - Misuzu Okajima
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu, Japan
| | | | - Naoto Ito
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu, Japan
| | - Takashi Mori
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu, Japan.,Animal Medical Center, Gifu University, Gifu, Gifu, Japan
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Morinaga Y, Akutsu H, Kino H, Tanaka S, Miyamoto H, Matsuda M, Yasuda M, Ishikawa E. Endoscopic endonasal extreme far-medial approach for a lower clivus osteochondroma in a patient with hereditary multiple exostoses: illustrative case. JOURNAL OF NEUROSURGERY: CASE LESSONS 2021; 1:CASE2153. [PMID: 35855014 PMCID: PMC9245849 DOI: 10.3171/case2153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 02/19/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND The authors reported on the use of endoscopic endonasal surgery (EES) for clivus osteochondroma in a patient with hereditary multiple exostoses (HME), a rare pediatric disorder characterized by the formation of osteochondromas adjacent to the growth plates of the axial and appendicular skeletal elements. OBSERVATIONS A 26-year-old man with a family history of HME reported progressive hoarseness and dysphagia over the previous 6 months. He was referred to us after magnetic resonance imaging (MRI) showed a bone tumor in the lower clivus. MRI revealed tumor proliferation in the lower clivus and its extension to the bilateral occipital condyle and jugular tubercle. The hypoglossal canal and jugular foramen were encased on the right side, whereas the medulla oblongata was compressed. The tumor was subtotally resected with EES, and the brainstem was successfully decompressed. The pathological diagnosis was exostoses. Transient postoperative worsening of dysphagia improved within 1 month without other neurological deficits. The patient underwent posterior occipitoaxial fixation 3 months after EES to correct instability and local lateral tilt of the right atlanto-occipital joint. LESSONS The authors’ experience showed that EES is effective for resection of lower clivus osteochondromas, including the cartilaginous cap, and may improve clinical outcomes in patients with HME.
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Affiliation(s)
| | | | | | - Shuho Tanaka
- Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan; and
| | - Hidetaka Miyamoto
- Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan; and
| | | | - Muneyoshi Yasuda
- Department of Neurosurgery, Ichinomiyanishi Hospital, Ichinomiya, Aichi, Japan
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Wang Y, Zhong L, Xu Y, Ding L, Ji Y, Schutz S, Férec C, Cooper DN, Xu C, Chen JM, Luo Y. EXT1 and EXT2 Variants in 22 Chinese Families With Multiple Osteochondromas: Seven New Variants and Potentiation of Preimplantation Genetic Testing and Prenatal Diagnosis. Front Genet 2020; 11:607838. [PMID: 33414810 PMCID: PMC7783290 DOI: 10.3389/fgene.2020.607838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/02/2020] [Indexed: 11/13/2022] Open
Abstract
Multiple osteochondromas (MO), the most common type of benign bone tumor, is an autosomal dominant skeletal disorder characterized by multiple cartilage-capped bony protuberances. In most cases, EXT1 and EXT2, which encode glycosyltransferases involved in the biosynthesis of heparan sulfate, are the genes responsible. Here we describe the clinical, phenotypic and genetic characterization of MO in 22 unrelated Chinese families involving a total of 60 patients. Variant detection was performed by means of a battery of different techniques including Sanger sequencing and whole-exome sequencing (WES). The pathogenicity of the missense and splicing variants was explored by means of in silico prediction algorithms. Sixteen unique pathogenic variants, including 10 in the EXT1 gene and 6 in the EXT2 gene, were identified in 18 (82%) of the 22 families. Fourteen (88%) of the 16 variants were predicted to give rise to truncated proteins whereas the remaining two were missense. Seven variants were newly described here, further expanding the spectrum of MO-causing variants in the EXT1 and EXT2 genes. More importantly, the identification of causative variants allowed us to provide genetic counseling to 8 MO patients in terms either of preimplantation genetic testing (PGT) or prenatal diagnosis, thereby preventing the reoccurrence of MO in the corresponding families. This study is the first to report the successful implementation of PGT in MO families and describes the largest number of subjects undergoing prenatal diagnosis to date.
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Affiliation(s)
- Ye Wang
- Fetal Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Liangying Zhong
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yan Xu
- Reproductive Medicine Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangzhou, China
| | - Lei Ding
- Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yuanjun Ji
- Fetal Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Sacha Schutz
- Inserm, Univ Brest, EFS, UMR 1078, GGB, Brest, France
- CHRU Brest, Brest, France
| | - Claude Férec
- Inserm, Univ Brest, EFS, UMR 1078, GGB, Brest, France
- CHRU Brest, Brest, France
| | - David N. Cooper
- School of Medicine, Institute of Medical Genetics, Cardiff University, Cardiff, United Kingdom
| | - Caixia Xu
- Research Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jian-Min Chen
- Inserm, Univ Brest, EFS, UMR 1078, GGB, Brest, France
| | - Yanmin Luo
- Fetal Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Matsumoto K, Ogawa H, Nozawa S, Akiyama H. An analysis of osteoporosis in patients with hereditary multiple exostoses. Osteoporos Int 2020; 31:2355-2361. [PMID: 32642853 DOI: 10.1007/s00198-020-05533-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/01/2020] [Indexed: 11/30/2022]
Abstract
UNLABELLED We analyzed osteoporosis in 20 HME patients. According to the T-score of BMD, 30% and 67.5% of the patients fell in the range of osteopenia in the lumbar spine and femoral neck. Our results indicate HME patients have low bone mass. They do not have abnormal bone metabolism. INTRODUCTION There are few reports of osteoporosis in hereditary multiple exostoses (HME) patients. Therefore, the purpose of this study was to analyze osteoporosis in HME patients. METHODS This retrospective cohort study included 20 patients diagnosed with HME. Patients underwent bone mineral density (BMD) measurement of the lumbar spine (n = 20) and femoral neck (n = 40). Bone metabolic parameters, including serum osteocalcin and urinary cross-linked N-telopeptide of type 1 collagen (NTx), were analyzed in all subjects. EXT1 and EXT2 genes were sequenced using genomic DNA. We also examined the correlation between genotype and BMD Z-score and T-score. RESULTS The mean BMD values of the lumbar spine were 1.085 ± 0.116 g/cm2 (n = 11) in male and 1.108 ± 0.088 g/cm2 (n = 9) in female. The mean BMD values of the femoral neck area were 0.759 ± 0.125 g/cm2 (n = 22) in male and 0.749 ± 0.115 g/cm2 (n = 18) in female. Z-score of most HME patients show < 0, indicating that these patients tend to have low bone mass compared with the age-matched population. According to the T-score of BMD, 30% (6 of 20) and 67.5% (27 of 40) of the patients fell in the range of osteopenia in the lumbar spine and femoral neck areas, respectively. Serum osteocalcin and urinary NTx were in the normal range in most patients. There was no significant correlation between genotypes and Z-score. CONCLUSION HME patients have low bone mass, especially in the femoral neck area. They do not have abnormal bone metabolism, and there was no correlation between genotypes and Z-score.
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Affiliation(s)
- K Matsumoto
- Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, 1-1, Yanagido, Gifu, 501-1194, Japan.
| | - H Ogawa
- Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, 1-1, Yanagido, Gifu, 501-1194, Japan
| | - S Nozawa
- Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, 1-1, Yanagido, Gifu, 501-1194, Japan
| | - H Akiyama
- Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, 1-1, Yanagido, Gifu, 501-1194, Japan
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Mordenti M, Shih F, Boarini M, Pedrini E, Gnoli M, Antonioli D, Tremosini M, Sangiorgi L. The natural history of multiple osteochondromas in a large Italian cohort of pediatric patients. Bone 2020; 139:115499. [PMID: 32592948 DOI: 10.1016/j.bone.2020.115499] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/04/2020] [Accepted: 06/14/2020] [Indexed: 12/17/2022]
Abstract
IMPORTANCE Multiple osteochondromas is a rare hereditary skeletal disorder, characterized by bony protrusions arising from growth plates on long bones during skeletal development. The disorder frequently leads to diminished stature, deformities and functional limitations. Understanding of the natural history of multiple osteochondromas and its evolution in children and adolescents is limited. OBJECTIVE To provide valuable information on the natural history of multiple osteochondromas, to inform recommendations for treatment and prevent impairments caused by osteochondromas. DESIGN This retrospective cohort study in children with multiple osteochondromas includes longitudinal data collected from first to last follow-up visit for patient demographics, and over 36 months for disease evolution. SETTING Data were collected from the Registry of Multiple Osteochondromas, which includes data from circa 1200 patients with multiple osteochondromas treated from 2003 to 2017 at IRCCS Istituto Ortopedico Rizzoli in Bologna. PARTICIPANTS Patients ≤18 years with multiple osteochondromas, who provided written informed consent and had data for ≥1 12-month follow-up visit. MAIN OUTCOME(S) AND MEASUREMENT(S) Demographics, clinical features, incidence of surgeries, and disease evolution (progression or regression) were assessed. Results were summarized using descriptive statistics, annual rates of new clinical features and surgeries, and Kaplan-Meier estimates. Patient height was evaluated following Italian growth charts. RESULTS 158 patients were included in these analyses. Throughout follow-up, 80.4% of patients developed new osteochondromas, 57.6% developed new deformities, 23.4% developed new functional limitation(s). New osteochondroma(s) were developed by 28.5% patients by Month 12, 39.9% at Month 24, 50% at Month 36. Most new osteochondromas were detected in the younger population; patients aged 0-4 years underwent a significantly higher number of lesions within 12, 24 and 36 months of follow-up. The overall incidence of patients with ≥1 new deformity within 12 months was 17.7%, with incidences decreasing with increasing age (p = .023). In addition, the analyses on height highlight that 13 years is a cut off age for slow growth of the stature (p < .0005). At last follow-up visit, 46.2% of patients had disease progression, while regression (spontaneous and surgical) occurred in 7.6% (p = .007). CONCLUSIONS AND RELEVANCE This natural history study reports the main set of clinically relevant data for patients with multiple osteochondromas during skeletal development, providing insight for patient management and development of therapeutic interventions.
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Affiliation(s)
- Marina Mordenti
- Department of Medical Genetics and Rare Orthopedic Diseases and CLIBI Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | | | - Manila Boarini
- Department of Medical Genetics and Rare Orthopedic Diseases and CLIBI Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | - Elena Pedrini
- Department of Medical Genetics and Rare Orthopedic Diseases, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | - Maria Gnoli
- Department of Medical Genetics and Rare Orthopedic Diseases, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | - Diego Antonioli
- Ward of Pediatric Orthopedics and Traumatology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | - Morena Tremosini
- Department of Medical Genetics and Rare Orthopedic Diseases, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
| | - Luca Sangiorgi
- Department of Medical Genetics and Rare Orthopedic Diseases and CLIBI Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
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Long X, Li Z, Huang Y, Zhang L, Lv W, Teng Y, Linpeng S, Liang D, Wu L. Identification of pathogenic mutations in 6 Chinese families with multiple exostoses by whole-exome sequencing and multiplex ligation-dependent probe amplification: Case series. Medicine (Baltimore) 2019; 98:e15692. [PMID: 31096510 PMCID: PMC6531242 DOI: 10.1097/md.0000000000015692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
RATIONALE Hereditary multiple exostoses (HMEs) is an autosomal dominant skeletal disorder. PATIENT CONCERNS Six probands of the 6 unrelated Han Chinese families were identified as having HME. These patients had exostoses at multiple sites and significantly affected joints malformation and movement. DIAGNOSES Hereditary multiple exostoses. INTERVENTIONS To detect the genetic mechanism of HME in 6 unrelated Chinese families, whole-exome sequencing (WES) and multiplex ligation-dependent probe amplification (MLPA) were used after genomic DNA was isolated from peripheral blood leucocytes. Point mutations identified by these methods were verified by Sanger sequencing after PCR amplification. OUTCOMES Six mutations in the EXT1 and EXT2 genes were identified, including a heterozygous deletion mutation from exon 2 to exon 8 (Family 1), a c.448C>T, p.(Gln150X) heterozygous nonsense mutation (Family 4), a c.1057-2A>T heterozygous splicing substitution (Family 5), and a c.1468dupC, p.(Leu490fs519X) (Family 6) heterozygous duplication mutation in the EXT1 gene in addition to a heterozygous deletion mutation from exon 2 to exon 3 (Family 2) and a c.1197C>G, p.(Tyr399X) heterozygous nonsense mutation (Family 3) in the EXT2 gene. LESSONS Overall, we identified 5 novel mutations and 1 recurrent mutation in the EXT1 and EXT2 genes in 6 Chinese families with HME. Our findings expand the mutational spectrum of the EXT1 and EXT2 genes and are useful for genetic counseling and prenatal diagnosis.
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Affiliation(s)
- Xigui Long
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University
| | - Zhuo Li
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University
| | - Yanru Huang
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University
| | - Li Zhang
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University
| | - Weigang Lv
- Hunan Jiahui Genetics Hospital, Changsha, Hunan, PR China
| | - Yanling Teng
- Hunan Jiahui Genetics Hospital, Changsha, Hunan, PR China
| | - Siyuan Linpeng
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University
| | - Desheng Liang
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University
- Hunan Jiahui Genetics Hospital, Changsha, Hunan, PR China
| | - Lingqian Wu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University
- Hunan Jiahui Genetics Hospital, Changsha, Hunan, PR China
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Yang A, Kim J, Jang JH, Lee C, Lee JE, Cho SY, Jin DK. Identification of a novel mutation in EXT2 in a fourth-generation Korean family with multiple osteochondromas and overview of mutation spectrum. Ann Hum Genet 2019; 83:160-170. [PMID: 30730578 DOI: 10.1111/ahg.12298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/31/2018] [Accepted: 12/17/2018] [Indexed: 12/01/2022]
Abstract
Multiple osteochondromas (MOs) or hereditary multiple exostoses is a rare autosomal-dominant disease characterized by growths of MOs, which are benign cartilage-capped bone tumors that grow away from the growth plates. Almost 90% of MOs have a molecular explanation and 10% are unexplained. MOs are genetically heterogeneous with two causal genes on 8q24.11 (EXT1) and 11p12 (EXT2), with a higher frequency in EXT1. MO is a very rare genetic disorder, and the genotype-phenotype of MO with EXT2 mutation has not been well investigated in Korea. We present the clinical radiographic and molecular analysis of a four-generation Korean family with 11 MO-affected members (seven males and four females). The affected members from the third generation available for molecular analysis and their detailed medical histories showed moderate-to-severe phenotypes (clinical classes II-III), including bony deformities and limb misalignment with pain requiring surgical correction. The x-rays showed MOs in multiple sites. A novel EXT2 frameshift mutation (c.590delC, p.P197Qfs*73) was revealed by targeted exome sequencing in the affected members of this family. In this article, we not only expand the phenotypic-genotypic spectrum of MOs but also highlight the phenotypic heterogeneity in a family with the same mutation. In addition, we compiled the mutation spectrum of EXT2 from a literature review and identified that exon 2 of EXT2 is a mutation hot spot. Early medical attention with diagnosis of MO through careful examination of the clinical manifestations and genetic analysis can provide the opportunity to establish coordinated multispecialty management of the patient.
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Affiliation(s)
- Aram Yang
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jinsup Kim
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Ja-Hyun Jang
- Green Cross Genome, Yongin-si, Republic of Korea
| | - Chung Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Samsung Genome Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Ji-Eun Lee
- Department of Pediatrics, Inha University Hospital, Inha University Graduate School of Medicine, Incheon, Republic of Korea
| | - Sung Yoon Cho
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Dong-Kyu Jin
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Santos SCL, Rizzo IMPO, Takata RI, Speck‐Martins CE, Brum JM, Sollaci C. Analysis of mutations in EXT1 and EXT2 in Brazilian patients with multiple osteochondromas. Mol Genet Genomic Med 2018. [PMID: 29529714 PMCID: PMC6014457 DOI: 10.1002/mgg3.382] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background Multiple osteochondromas is a dysplasia characterized by growth of two or more osteochondromas. It is genetically heterogeneous, caused by pathogenic variants in EXT1 or EXT2 genes in 70%–90% of patients. The EXT1 is more often mutated than EXT2 gene, with a variable prevalence between populations. There are no data about EXT1 and EXT2 pathogenic variants in patients with multiple osteochondromas in Brazilian population. The aim of this survey is to characterize these to determine the genotype profile of this population. Methods DNA sequencing (Sanger Method) and MLPA analysis were performed to identify point mutations and deletions/duplications in the sample of 153 patients in 114 families. Results Germline variants were identified in 83% of families in which EXT2 variants were detected in 46% and EXT1 in 37% of cases. No variants were detected in 17% of them. We identified 50 different variants, 33 (13 frameshift, 11 nonsense, 5 missense, 2 splice site mutation, and 2 large deletions) in EXT1 and 17 (6 frameshift, 6 splice site mutation, 3 nonsense, 1 missense, and 1 large deletion) in EXT2. Of all 50 variants, 31 (62%) were novel, including 20 out of 33 (60,6%) EXT1 and 11 out of 17 (64.7%) EXT2 alleles. The vast majority of variants (88%) were “loss‐of‐function” and two novel hotspots in EXT2 gene were observed in our study. Conclusion The prevalence of variants detected in the EXT2 gene differs from other researches from Latin America, European, and Asian population. This uncommon prevalence could be related with the newly characterized variant hotspot sites detected in EXT2 gene (p.Ala409Profs*26 and p.Ser290*). A high number of novel variants were also identified indicating that Brazilian population has a unique genetic profile. Characterizing this population and establishing its genotype is essential to understand the molecular pathogenesis of this disease in Brazil.
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Affiliation(s)
- Savana C. L. Santos
- Molecular Pathology LaboratorySARAH Network of Rehabilitation HospitalsBrasíliaBrazil
| | | | - Reinaldo I. Takata
- Molecular Pathology LaboratorySARAH Network of Rehabilitation HospitalsBrasíliaBrazil
| | | | - Jaime M. Brum
- Department of Clinical GeneticsSARAH Network of Rehabilitation HospitalsBrasíliaBrazil
| | - Claudio Sollaci
- Department of OrthopaedicsSARAH Network of Rehabilitation HospitalsBrasíliaBrazil
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11
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Tong K, Liu H, Wang X, Zhong Z, Cao S, Zhong C, Yang Y, Wang G. Osteochondroma: Review of 431 patients from one medical institution in South China. J Bone Oncol 2017; 8:23-29. [PMID: 28932679 PMCID: PMC5587240 DOI: 10.1016/j.jbo.2017.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/14/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The geographic distribution of osteochondroma (OC) varies greatly around the world. There has been no recent report on OC in a large Chinese population. The aim of this study was to characterize OC by an epidemiological analysis of the clinical data from one medical institution in South China. METHODS We searched medical electronic records from January 2001 to January 2016 in one large hospital in South China to identify patients with a definite diagnosis of OC. Their epidemiological data were collected and analyzed statistically, including gender, tumor site, age at first diagnosis and symptoms, local recurrence and malignant transformation. Differences between genders and between solitary osteochondroma (SO) and multiple osteochondroma (MO) were particularly analyzed. RESULTS A total of 431 OC patients (291 males and 140 females; 329 SOs and 102 MOs) were identified. The gender ratio was 2.08 with a male predominance. OCs were mostly located around the knee (250 cases). 280 patients were in their 0s to 20s upon first diagnosis. The average age at the time of first diagnosis was 20.63 years for all, 18.47 years for males and 25.11 years for females (P=0.000). OC recurred locally in 35 patients (15 SOs and 20 MOs), with a significant difference between SO/MO (P=0.000) but not between genders (P=0.100). The average interval from the primary surgery to local or malignant recurrence was 37.41 months. Malignant transformation was found in 5 patients (4 males and 1 female), showing no gender difference (P=0.549). CONCLUSIONS OC may have a male predominance in Chinese population. It mostly occurred at 0-20 years of age and around the knee. Upon the first diagnosis of OC, the males tended to be younger than the females, and so did the MO patients than the SO ones. In addition, MO had a higher incidence of local recurrence. Intervals from primary surgery to local recurrence or malignant transformation in MO patients were longer than in SO patients.
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Affiliation(s)
- Kai Tong
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Hongzhe Liu
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Xiang Wang
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Ziyi Zhong
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Shenglu Cao
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Chengjie Zhong
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - YunPing Yang
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Gang Wang
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China
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Xu Y, Kang Q, Zhang Z. Identification of mutations in EXT1 and EXT2 genes in six Chinese families with multiple osteochondromas. Mol Med Rep 2017; 16:5599-5605. [PMID: 28849184 DOI: 10.3892/mmr.2017.7252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 06/09/2017] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to identify mutations of major causative genes in six unrelated Chinese families with multiple osteochondromas (MO). Radiographic examinations and genetic analyses were performed in 8 patients exhibiting typical features of MO. Analysis was also performed on unaffected members of the six families and 250 healthy volunteers. Radiographies of the patients revealed multiple exostoses in the cartilage of long bones. A total of five different mutations were identified, one in exostosin‑1 (EXT1) and four in exostosin‑2 (EXT2). Two novel mutations were detected in EXT2: A missense mutation, c.1385G>A, in exon 8, resulting in p.Trp462X; and a splice site mutation, c.725+1G>C, which consisted of a heterozygous guanine‑to‑cytosine transition at nucleotide 725+1 in intron 3. Three common EXT mutations were also detected: c.1036C>T in exon 5 of EXT2 resulting in p.Gln346X; c.1299C>A in exon 8 of EXT2 resulting in p.Phe433Leu; and c.1038A>T in exon 2 of EXT1 resulting in p.Arg346Ser. In conclusion, the present study identified a novel missense mutation (c.1385G>A) in exon 8 and a splicing mutation (c.725+1G>C) in intron 3 of the EXT2 gene, which are responsible for MO in certain Chinese patients. The findings are useful for expanding the database of known EXT2 mutations and understanding the genetic basis of MO in Chinese patients, which may improve genetic counseling and the prenatal diagnosis of MO.
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Affiliation(s)
- Yang Xu
- Department of Osteoporosis and Bone Diseases, Metabolic Bone Disease and Genetics Research Unit, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Qinglin Kang
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
| | - Zhenlin Zhang
- Department of Osteoporosis and Bone Diseases, Metabolic Bone Disease and Genetics Research Unit, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China
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13
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Cousminer DL, Arkader A, Voight BF, Pacifici M, Grant SFA. Assessing the general population frequency of rare coding variants in the EXT1 and EXT2 genes previously implicated in hereditary multiple exostoses. Bone 2016; 92:196-200. [PMID: 27616605 PMCID: PMC5056851 DOI: 10.1016/j.bone.2016.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 09/07/2016] [Indexed: 10/21/2022]
Abstract
Hereditary multiple exostoses (HME) is a rare childhood-onset skeletal disease linked to mutations in exostosin glycosyltransferase 1 (EXT1) or 2 (EXT2). Patients are heterozygous for either an EXT1 or EXT2 mutation, and it is widely assumed that exostosis formation and associated defects, such as growth retardation and skeletal deformities, require loss-of-heterozygosity or a second hit in affected cells. However, the relevance and phenotypic impact of many presumed pathogenic EXT variants remain uncertain. We extracted all amino acid-altering (missense) and loss of function (LoF; nonsense, frameshift, or splice-site) variants from the Exome Aggregation Consortium (ExAC), a large population-based repository of exome sequence data from diverse ancestries that has screened out severe pediatric disease, to assess the overall mutation spectrum of predicted protein-damaging variants across these two genes in the general population. We then determined whether clinically-identified, presumably pathogenic variants implicated in HME exist among healthy individuals. We found six EXT1 and four EXT2 missense mutations in ExAC, suggesting that these mutations have either been misclassified as pathogenic or are not fully penetrant. Furthermore, EXT1 is heavily selectively constrained, while EXT2 is more tolerant to protein-damaging variants, especially at its C-terminus, possibly explaining the genotype-phenotype correlation that EXT1 variants usually result in more severe disease. In conclusion, population-based exome data is a useful filter for determining whether clinically detected variants are likely pathogenic, as well as revealing biological insight into rare disease genes such as EXT1 and EXT2.
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Affiliation(s)
- Diana L Cousminer
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, USA; Department of Genetics, University of Pennsylvania, Philadelphia, USA.
| | - Alexandre Arkader
- Division of Orthopedic Surgery, Children's Hospital of Philadelphia, Perelman School of Medicine at University of Pennsylvania, USA
| | - Benjamin F Voight
- Department of Genetics, University of Pennsylvania, Philadelphia, USA; Department of Systems Pharmacology and Translation Therapeutics, University of Pennsylvania, Philadelphia, USA; Institute of Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, USA
| | - Maurizio Pacifici
- Division of Orthopedic Surgery, Children's Hospital of Philadelphia, Perelman School of Medicine at University of Pennsylvania, USA
| | - Struan F A Grant
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, USA; Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA; Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, USA.
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14
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Chen XJ, Zhang H, Tan ZP, Hu W, Yang YF. Novel mutation of EXT2 identified in a large family with multiple osteochondromas. Mol Med Rep 2016; 14:4687-4691. [PMID: 27748933 PMCID: PMC5102042 DOI: 10.3892/mmr.2016.5814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 09/20/2016] [Indexed: 12/24/2022] Open
Abstract
Multiple osteochondromas (MO), also known as hereditary multiple exostoses, is an autosomal dominant bone disorder. Mutations in exostosin glycosyl transferase-1 (EXT1) and exostosin glycosyl transferase-2 (EXT2), including missense, nonsense, frameshift and splice-site mutations, account for up to 80% of reported cases. The proteins EXT1 and EXT2 form a hetero-oligomeric complex that functions in heparan sulfate proteoglycan biosynthesis. A heterozygous EXT2 mutation, c.939+1G>T, was identified in a five-generation 33-member MO family, and was present in all 13 affected members. The mutation results in deletion of exon 5 in the mRNA, producing a frameshift that leads to a premature termination codon. The present study extends the mutational spectrum of EXT2.
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Affiliation(s)
- Xiao-Jun Chen
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Hong Zhang
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Zhi-Ping Tan
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Wen Hu
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Yi-Feng Yang
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
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15
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Ishimaru D, Gotoh M, Takayama S, Kosaki R, Matsumoto Y, Narimatsu H, Sato T, Kimata K, Akiyama H, Shimizu K, Matsumoto K. Large-scale mutational analysis in the EXT1 and EXT2 genes for Japanese patients with multiple osteochondromas. BMC Genet 2016; 17:52. [PMID: 26961984 PMCID: PMC4784393 DOI: 10.1186/s12863-016-0359-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 03/01/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Multiple osteochondroma (MO) is an autosomal dominant skeletal disorder characterized by the formation of multiple osteochondromas, and exostosin-1 (EXT1) and exostosin-2 (EXT2) are major causative genes in MO. In this study, we evaluated the genetic backgrounds and mutational patterns in Japanese families with MO. RESULTS We evaluated 112 patients in 71 families with MO. Genomic DNA was isolated from peripheral blood leucocytes. The exons and exon/intron junctions of EXT1 and EXT2 were directly sequenced after PCR amplification. Fifty-two mutations in 47 families with MO in either EXT1 or EXT2, and 42.3% (22/52) of mutations were novel mutations. Twenty-nine families (40.8%) had mutations in EXT1, and 15 families (21.1%) had mutations in EXT2. Interestingly, three families (4.2%) had mutations in both EXT1 and EXT2. Twenty-four families (33.8%) did not exhibit mutations in either EXT1 or EXT2. With regard to the types of mutations identified, 59.6% of mutations were inactivating mutations, and 38.5% of mutations were missense mutations. CONCLUSIONS We found that the prevalence of EXT1 mutations was greater than that of EXT2 mutations in Japanese MO families. Additionally, we identified 22 novel EXT1 and EXT2 mutations in this Japanese MO cohort. This study represents the variety of genotype in MO.
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Affiliation(s)
- Daichi Ishimaru
- Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, 1-1, Yanagido, Gifu, 501-1194, Japan.
| | - Masanori Gotoh
- Research Center for Medical Glycoscience (RCMG), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.
| | - Shinichiro Takayama
- Department of Orthopedic Surgery, National Research Institute for Child Health and Development, Tokyo, Japan.
| | - Rika Kosaki
- Division of Medical Genetics, National Center for Child Health and Development, Tokyo, Japan.
| | - Yoshihiro Matsumoto
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Hisashi Narimatsu
- Research Center for Medical Glycoscience (RCMG), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.
| | - Takashi Sato
- Research Center for Medical Glycoscience (RCMG), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.
| | - Koji Kimata
- Advanced Medical Research Center, Aichi Medical University, Nagakute, Aichi, Japan.
| | - Haruhiko Akiyama
- Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, 1-1, Yanagido, Gifu, 501-1194, Japan.
| | | | - Kazu Matsumoto
- Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, 1-1, Yanagido, Gifu, 501-1194, Japan.
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16
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Malini K, Gudi NS, Kutty AVM, Balakrishna S. Mutational Analysis of Exostosin 1 and 2 Genes in Multiple Osteochondroma. Indian J Pediatr 2015; 82:649-50. [PMID: 25591329 DOI: 10.1007/s12098-014-1675-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/22/2014] [Indexed: 11/25/2022]
Affiliation(s)
- K Malini
- Genome Lab, Department of Cell Biology and Molecular Genetics, Faculty of Allied Health Sciences, Sri Devaraj Urs Academy of Higher Education and Research, Tamaka, Kolar, Karnataka, 563101, India
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17
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Musso N, Caronia FP, Castorina S, Lo Monte AI, Barresi V, Condorelli DF. Somatic loss of an EXT2 gene mutation during malignant progression in a patient with hereditary multiple osteochondromas. Cancer Genet 2015; 208:62-7. [PMID: 25744876 DOI: 10.1016/j.cancergen.2015.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/19/2014] [Accepted: 01/11/2015] [Indexed: 10/24/2022]
Abstract
Multiple osteochondromas (MO) is an autosomal-dominant skeletal disorder caused by mutations in the exostosin-1 (EXT1) or exostosin-2 (EXT2) genes. In this study, we report the analysis of the mutational status of the EXT2 gene in tumor samples derived from a patient affected by hereditary MO, documenting the somatic loss of the germline mutation in a giant chondrosarcoma and in a rapidly growing osteochondroma. The sequencing of all exons and exon-intron junctions of the EXT1 and EXT2 genes from blood DNA of the proband did not reveal any mutation in the EXT1 gene but did demonstrate the presence of the transition point mutation c.67C > T in the EXT2 gene, determining the introduction of a stop codon in the coding sequence (p.Arg23*). A mutational analysis of other members of the family and the presence of osteochondromas in the metaphysis of long bones confirmed the diagnosis of hereditary multiple osteochondromas. Direct sequencing from DNA extracted from different sites of two tumor samples (a small rapidly growing osteochondroma and a giant peripheral secondary chondrosarcoma, each located at different chondrocostal junctions) revealed the loss of the germline EXT2 mutation. Analysis of microsatellite polymorphic markers in the 11p region harboring the EXT2 gene did not reveal any loss of heterozygosity. This observation supports a recent model of sarcomagenesis in which osteochondroma cells bear EXT homozygous inactivation, whereas chondrosarcoma-initiating cells are EXT-expressing cells.
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Affiliation(s)
- Nicolò Musso
- Scuola Superiore di Catania, University of Catania, Catania, Italy; Department of Biomedical and Biotechnological Sciences, Section of Medical Biochemistry, University of Catania, Catania, Italy
| | - Francesco Paolo Caronia
- Dipartimento di Chirurgia Toracica, Centro Clinico e Diagnostico "G.B Morgagni", Catania, Italy
| | - Sergio Castorina
- Dipartimento di Chirurgia Toracica, Centro Clinico e Diagnostico "G.B Morgagni", Catania, Italy; Department of Biomedical and Biotechnological Sciences, Section of Human Anatomy and Histology, University of Catania, Catania, Italy
| | | | - Vincenza Barresi
- Scuola Superiore di Catania, University of Catania, Catania, Italy; Department of Biomedical and Biotechnological Sciences, Section of Medical Biochemistry, University of Catania, Catania, Italy
| | - Daniele Filippo Condorelli
- Scuola Superiore di Catania, University of Catania, Catania, Italy; Department of Biomedical and Biotechnological Sciences, Section of Medical Biochemistry, University of Catania, Catania, Italy.
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18
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Liu H, Wu S, Duan L, Zhu W, Zhang S, Hu X, Jia W, Yang G, Liu C, Li W, Yang L, Guo L, Lin Y, Wang Y, He M, Yang Z, He Y, Cai Z, Wang D. Identification of a novel EXT1 mutation in patients with hereditary multiple exostosis by exome sequencing. Oncol Rep 2014; 33:547-52. [PMID: 25421355 PMCID: PMC4306274 DOI: 10.3892/or.2014.3610] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 10/20/2014] [Indexed: 11/05/2022] Open
Abstract
Hereditary multiple exostosis (HME) is an autosomal inherited skeletal disease whose etiology is not fully understood. To further understand the genetic spectrum of the disease, we analyzed a five-generation Chinese family with HME that have observable inheritance. Exome sequencing was performed on three HME individuals and three unaffected individuals from the family. A downstream study confirmed a new C deletion at codon 442 on exon 5 of the exostosin-1 (EXT1) gene as the only pathogenic site which generated a stop codon and caused the truncation of the protein. We rediscovered the deletion in other affected individuals but not in the unaffected individuals from the family. Upon immunohistochemistry assay, we found that the EXT1 protein level of the patients with the novel mutation in our study was less than the level in the patients without the EXT1 mutation from another unrelated family. For a deeper understanding, we analyzed the mutation spectrum of the EXT1 gene. The present study should facilitate a further understanding of HME.
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Affiliation(s)
- Hongjie Liu
- College of Life Science, University of Chinese Academy of Sciences College, Beijing 100049, P.R. China
| | - Song Wu
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Li Duan
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Weiming Zhu
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Shiquan Zhang
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Xiaoxiao Hu
- College of Life Science, University of Chinese Academy of Sciences College, Beijing 100049, P.R. China
| | - Wenlong Jia
- BGI Tech Solutions Co., Ltd., Beishan Industrial Zone, Shenzhen 518083, P.R. China
| | - Guosheng Yang
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Chunxiao Liu
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Weiping Li
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Lei Yang
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Lijun Guo
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Youcheng Lin
- Department of Urology, Zhujiang Hospital of Southern Medical University, Guangzhou 510000, P.R. China
| | - Yongqiang Wang
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Meijian He
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Zhao Yang
- Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Yingying He
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Zhiming Cai
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
| | - Daping Wang
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518000, P.R. China
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A broad spectrum of genomic changes in latinamerican patients with EXT1/EXT2-CDG. Sci Rep 2014; 4:6407. [PMID: 25230886 PMCID: PMC4166712 DOI: 10.1038/srep06407] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 07/22/2014] [Indexed: 02/03/2023] Open
Abstract
Multiple osteochondromatosis (MO), or EXT1/EXT2-CDG, is an autosomal dominant O-linked glycosylation disorder characterized by the formation of multiple cartilage-capped tumors (osteochondromas). In contrast, solitary osteochondroma (SO) is a non-hereditary condition. EXT1 and EXT2, are tumor suppressor genes that encode glycosyltransferases involved in heparan sulfate elongation. We present the clinical and molecular analysis of 33 unrelated Latin American patients (27 MO and 6 SO). Sixty-three percent of all MO cases presented severe phenotype and two malignant transformations to chondrosarcoma (7%). We found the mutant allele in 78% of MO patients. Ten mutations were novel. The disease-causing mutations remained unknown in 22% of the MO patients and in all SO patients. No second mutational hit was detected in the DNA of the secondary chondrosarcoma from a patient who carried a nonsense EXT1 mutation. Neither EXT1 nor EXT2 protein could be detected in this sample. This is the first Latin American research program on EXT1/EXT2-CDG.
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20
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Mutational screening of EXT1 and EXT2 genes in Polish patients with hereditary multiple exostoses. J Appl Genet 2014; 55:183-8. [PMID: 24532482 PMCID: PMC3990859 DOI: 10.1007/s13353-014-0195-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 01/14/2014] [Accepted: 01/15/2014] [Indexed: 11/26/2022]
Abstract
Hereditary multiple exostoses (HME) also known as multiple osteochondromas represent one of the most frequent bone tumor disorder in humans. Its clinical presentation is characterized by the presence of multiple benign cartilage-capped tumors located most commonly in the juxta-epiphyseal portions of long bones. HME are usually inherited in autosomal dominant manner, however de novo mutations can also occur. In most patients, the disease is caused by alterations in the EXT1 and EXT2 genes. In this study we investigated 33 unrelated Polish probands with the clinical and radiological diagnosis of HME by means of Sanger sequencing and MLPA for all coding exons of EXT1 and EXT2. We demonstrated EXT1 and EXT2 heterozygous mutations in 18 (54.6 %) and ten (30.3 %) probands respectively, which represents a total of 28 (84.9 %) index cases. Sequencing allowed for the detection of causative changes in 26 (78.8 %) probands, whereas MLPA showed intragenic deletions in two (6.1 %) further cases (15 mutations represented novel changes). Our paper is the first report on the results of exhaustive mutational screening of both EXT1/EXT2 genes in Polish patients. The proportion of EXT1/EXT2 mutations in our group was similar to other Caucasian cohorts. However, we found that EXT1 lesions in Polish patients cluster in exons 1 and 2 (55.6 % of all EXT1 mutations). This important finding should lead to the optimization of cost-effectiveness rate of HME diagnostic testing. Therefore, the diagnostic algorithm for HME should include EXT1 sequencing (starting with exons 1–2), followed by EXT2 sequencing, and MLPA/qPCR for intragenic copy number changes.
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21
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Kang QL, Xu J, Zhang Z, He JW, Fu WZ, Zhang ZL. Mutation screening for the EXT1 and EXT2 genes in Chinese patients with multiple osteochondromas. Arch Med Res 2013; 44:542-8. [PMID: 24120389 DOI: 10.1016/j.arcmed.2013.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 09/19/2013] [Indexed: 12/26/2022]
Abstract
BACKGROUND AND AIMS Multiple osteochondromas (MO), an autosomal dominant skeletal disease, is characterized by the presence of multiple cartilage-capped bone tumors (exostoses). Two genes with mutations that are most commonly associated with MO have been identified as EXT1 and EXT2, which are Exostosin-1 and Exostosin-2. In this study, a variety of EXT1 and EXT2 gene mutations were identified in ten Chinese families with MO. METHODS We investigated ten unrelated Chinese families involving a total of 46 patients who exhibited typical features of MO. The coding exons of EXT1 and EXT2 were sequenced after PCR amplification in ten probands. Radiological investigation was conducted simultaneously. RESULTS Nine mutations were identified, five in EXT1 and four in EXT2, of which three were de novo mutations and six were novel mutations. One proband carried mutations in both EXT1 and EXT2 simultaneously, and three probands, including one sporadic case and two familial cases, had no detectable mutations. CONCLUSIONS Our findings are useful for extending the mutational spectrum in EXT1 and EXT2 and understanding the genetic basis of MO in Chinese patients.
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Affiliation(s)
- Qing-lin Kang
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, PR China
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22
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Wu Y, Xing X, Xu S, Ma H, Cao L, Wang S, Luo Y. Novel and recurrent mutations in the EXT1 and EXT2 genes in Chinese kindreds with multiple osteochondromas. J Orthop Res 2013; 31:1492-9. [PMID: 23629877 DOI: 10.1002/jor.22378] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/04/2013] [Indexed: 02/04/2023]
Abstract
Multiple osteochondromas (MO) is an autosomal dominant hereditary disorder caused by heterozygous germline mutations in the exostonsin-1 (EXT1) or exostosin-2 (EXT2) genes. In this study, we screened mutations in the EXT1/EXT2 genes in four Chinese MO kindreds by direct sequencing. Three point mutations were detected, including a nonsense mutation in the EXT2 gene (c.544C > T) and two splice site mutations in the EXT1 and EXT2 genes, respectively (EXT1: c.1883 + 1G > A and EXT2: c.1173 + 1G > T). Although splice site mutations constitute at least 10% of all mutations that cause MO, there has been limited research on their pathogenic effect on RNA processing due to poor availability of patient RNA samples. In this study, ex vivo and in vivo splicing assays were used to investigate the effect of EXT1 and EXT2 mutations on aberrant splicing at the mRNA level. Our results indicate that identified splice site mutations can cause either cryptic splice site usage or exon skipping.
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Affiliation(s)
- Yuhong Wu
- The Research Center for Medical Genomics, Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, 110001, China
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Zhang F, Liang J, Guo X, Zhang Y, Wen Y, Li Q, Zhang Z, Ma W, Dai L, Liu X, Yang L, Wang J. Exome sequencing and functional analysis identifies a novel mutation in EXT1 gene that causes multiple osteochondromas. PLoS One 2013; 8:e72316. [PMID: 24009674 PMCID: PMC3757002 DOI: 10.1371/journal.pone.0072316] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 07/10/2013] [Indexed: 11/19/2022] Open
Abstract
Multiple osteochondromas (MO) is an inherited skeletal disorder, and the molecular mechanism of MO remains elusive. Exome sequencing has high chromosomal coverage and accuracy, and has recently been successfully used to identify pathogenic gene mutations. In this study, exome sequencing followed by Sanger sequencing validation was first used to screen gene mutations in two representative MO patients from a Chinese family. After filtering the data from the 1000 Genome Project and the dbSNP database (build 132), the detected candidate gene mutations were further validated via Sanger sequencing of four other members of the same MO family and 200 unrelated healthy subjects. Immunohistochemisty and multiple sequence alignment were performed to evaluate the importance of the identified causal mutation. A novel frameshift mutation, c.1457insG at codon 486 of exon 6 of EXT1 gene, was identified, which truncated the glycosyltransferase domain of EXT1 gene. Multiple sequence alignment showed that codon 486 of EXT1 gene was highly conserved across various vertebrates. Immunohistochemisty demonstrated that the chondrocytes with functional EXT1 in MO were less than those in extragenetic solitary chondromas. The novel c.1457insG deleterious mutation of EXT1 gene reported in this study expands the causal mutation spectrum of MO, and may be helpful for prenatal genetic screening and early diagnosis of MO.
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Affiliation(s)
- Feng Zhang
- Key Laboratory of Environment and Gene Related Diseases of Ministry Education, Faculty of Public Health, College of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | | | - Xiong Guo
- Key Laboratory of Environment and Gene Related Diseases of Ministry Education, Faculty of Public Health, College of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, China
- * E-mail: (XG); (JW)
| | - Yingang Zhang
- Department of Orthopedics, First Affiliated Hospital of Medical College of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Yan Wen
- Key Laboratory of Environment and Gene Related Diseases of Ministry Education, Faculty of Public Health, College of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Qiang Li
- Department of Orthopedics, First People’s Hospital of Longxi County, Gansu, China
| | - Zengtie Zhang
- Key Laboratory of Environment and Gene Related Diseases of Ministry Education, Faculty of Public Health, College of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Weijuan Ma
- Key Laboratory of Environment and Gene Related Diseases of Ministry Education, Faculty of Public Health, College of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | | | | | | | - Jun Wang
- BGI-Shenzhen, Shenzhen, China
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
- King Abdulaziz University, Jeddah, Saudi Arabia
- * E-mail: (XG); (JW)
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Sarrión P, Sangorrin A, Urreizti R, Delgado A, Artuch R, Martorell L, Armstrong J, Anton J, Torner F, Vilaseca MA, Nevado J, Lapunzina P, Asteggiano CG, Balcells S, Grinberg D. Mutations in the EXT1 and EXT2 genes in Spanish patients with multiple osteochondromas. Sci Rep 2013; 3:1346. [PMID: 23439489 PMCID: PMC3581825 DOI: 10.1038/srep01346] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 02/07/2013] [Indexed: 11/15/2022] Open
Abstract
Multiple osteochondromas is an autosomal dominant skeletal disorder characterized by the formation of multiple cartilage-capped tumours. Two causal genes have been identified, EXT1 and EXT2, which account for 65% and 30% of cases, respectively. We have undertaken a mutation analysis of the EXT1 and EXT2 genes in 39 unrelated Spanish patients, most of them with moderate phenotype, and looked for genotype-phenotype correlations. We found the mutant allele in 37 patients, 29 in EXT1 and 8 in EXT2. Five of the EXT1 mutations were deletions identified by MLPA. Two cases of mosaicism were documented. We detected a lower number of exostoses in patients with missense mutation versus other kinds of mutations. In conclusion, we found a mutation in EXT1 or in EXT2 in 95% of the Spanish patients. Eighteen of the mutations were novel.
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Affiliation(s)
- P Sarrión
- Department of Genetics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, Spain
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25
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Mutation screening of EXT genes in Chinese patients with multiple osteochondromas. Gene 2012; 506:298-300. [DOI: 10.1016/j.gene.2012.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Revised: 06/25/2012] [Accepted: 07/06/2012] [Indexed: 12/24/2022]
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26
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Wang X, Li L, Li J, Sun J, Heng X, Gong Y, Liu Q. Pathogenic gene screening and mutation detection in a Chinese family with multiple osteochondroma. Genet Test Mol Biomarkers 2012; 16:827-32. [PMID: 22799611 DOI: 10.1089/gtmb.2011.0276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Multiple osteochondroma (MO) is an autosomal dominant disease characterized by abnormal skeleton development: one or more exostoses localized mainly at the end of long bones. Three pathogenic gene loci have been identified and cloned: EXT1, 2, and 3. Only EXT1 and 2 mutations were reported to cause MO. Here, we report on a large Chinese family with MO and a disease-causing mutation in EXT. We extracted DNA from peripheral blood samples of 25 family members, 9 with MO. Polymerase chain reaction and direct DNA sequencing of the entire coding regions of EXT1 and 2 for the nine patients revealed a novel pathogenic mutation, insertion of a T in exon 2 (c.72-73 insT) of EXT2. Our results extend the mutational spectrum of MO and can help with genetic counseling and prenatal diagnosis for this family.
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Affiliation(s)
- Xue Wang
- Key Laboratory for Experimental Teratology of the Ministry of Education, Department of Medical Genetics, Shandong University School of Medicine, Jinan, Republic of China
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27
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Jennes I, Zuntini M, Mees K, Palagani A, Pedrini E, De Cock G, Fransen E, Vanden Berghe W, Sangiorgi L, Wuyts W. Identification and functional characterization of the human EXT1 promoter region. Gene 2011; 492:148-59. [PMID: 22037484 DOI: 10.1016/j.gene.2011.10.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 10/02/2011] [Accepted: 10/11/2011] [Indexed: 01/02/2023]
Abstract
BACKGROUND Mutations in Exostosin-1 (EXT1) or Exostosin-2 (EXT2) cause the autosomal dominant disorder multiple osteochondromas (MO). This disease is mainly characterized by the appearance of multiple cartilage-capped protuberances arising from children's metaphyses and is known to display clinical inter- and intrafamilial variations. EXT1 and EXT2 are both tumor suppressor genes encoding proteins that function as glycosyltransferases, catalyzing the biosynthesis of heparan sulfate. At present, however, very little is known about the regulation of these genes. Two of the most intriguing questions concerning the pathogenesis of MO are how disruption of a ubiquitously expressed gene causes this cartilage-specific disease and how the clinical intrafamilial variation can be explained. Since mutations in the EXT1 gene are responsible for ~65% of the MO families with known causal mutation, our aim was to isolate and characterize the EXT1 promoter region to elucidate the transcriptional regulation of this tumor suppressor gene. METHODS In the present study, luciferase reporter gene assays were used to experimentally confirm the in silico predicted EXT1 core promoter region. Subsequently, we evaluated the effect of single nucleotide polymorphisms (SNP's) on EXT1 promoter activity and transcription factor binding using luciferase assays, electrophoretic mobility shift assays (EMSA), and enzyme-linked immunosorbent assays (ELISA). Finally, a genotype-phenotype study was performed with the aim to identify one or more genetic modifiers influencing the clinical expression of MO. RESULTS Transient transfection of HEK293 cells with a series of luciferase reporter constructs mapped the EXT1 core promoter at approximately -917 bp upstream of the EXT1 start codon, within a 123 bp region. This region is conserved in mammals and located within a CpG-island containing a CAAT- and a GT-box. A polymorphic G/C-SNP at -1158 bp (rs34016643) was demonstrated to be located in a USF1 transcription factor binding site, which is lost with the presence of the C-allele resulting in a ~56% increase in EXT1 promoter activity. A genotype-phenotype study was suggestive for association of the C-allele with shorter stature, but also with a smaller number of osteochondromas. CONCLUSIONS We provide for the first time insight into the molecular regulation of EXT1. Although a larger patient population will be necessary for statistical significance, our data suggest the polymorphism rs34016643, in close proximity of the EXT1 promoter, to be a potential regulatory SNP, which could be a primary modifier that might explain part of the clinical variation observed in MO patients.
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Affiliation(s)
- Ivy Jennes
- Department of Medical Genetics, University of Antwerp, and Antwerp University Hospital, Edegem, Belgium
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28
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Hamouda HI, Abulhasan S, Al-awadi S. Hereditary multiple exostoses, macrocephaly, congenital heart disease, developmental delay, and mental retardation in a female patient: A possible new syndrome? Or new association? EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2011. [DOI: 10.1016/j.ejmhg.2011.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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29
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Yang L, Hui WS, Chan WCW, Ng VCW, Yam THY, Leung HCM, Huang JD, Shum DKY, Jie Q, Cheung KMC, Cheah KSE, Luo Z, Chan D. A splice-site mutation leads to haploinsufficiency of EXT2 mRNA for a dominant trait in a large family with multiple osteochondromas. J Orthop Res 2010; 28:1522-30. [PMID: 20872591 DOI: 10.1002/jor.21162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Multiple osteochondromas (MO) is an autosomal-dominant disorder and mutations in EXT1 and EXT2 account up to 78% of the cases studied, including missense, nonsense, frameshift, and splice-site mutations. EXT1 and EXT2 encode glycosyltransferases required for the synthesis of heparan sulfate (HS) chains. The molecular pathogenesis underlying these mutations is still largely unknown. A heterozygous c.1173 + 1G > T (EXT2) mutation was identified in a three-generation 34-member MO family and is present in all 19 affected members. The consequence of this mutation is exon 7 being spliced out, and the result is a shift in the codon-reading frame from position 360 (R360) of the amino acid sequence leading to a premature termination codon, and the mutant mRNA is degraded to an undetectable level. Interestingly, HS glycosaminoglycans were also undetectable in the cartilage cap of the tumors by immunostaining. Full penetrance of this mutation in all affected members ranging from 5 to 70 years of age suggests this primary defect in EXT2 mRNA level, in conjunction with other cellular changes such as enhanced heparanase expression, can produce profound effect on the synthesis of HS chains in cartilage, the consequence of which impacts on the regulation of chondrocyte proliferation and differentiation.
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Affiliation(s)
- Liu Yang
- Department of Biochemistry, University of Hong Kong, Pokfulam, Hong Kong, China
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30
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Jennes I, Pedrini E, Zuntini M, Mordenti M, Balkassmi S, Asteggiano CG, Casey B, Bakker B, Sangiorgi L, Wuyts W. Multiple osteochondromas: mutation update and description of the multiple osteochondromas mutation database (MOdb). Hum Mutat 2010; 30:1620-7. [PMID: 19810120 DOI: 10.1002/humu.21123] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Multiple osteochondromas (MO) is an autosomal dominant skeletal disease characterized by the formation of multiple cartilage-capped bone tumors growing outward from the metaphyses of long tubular bones. MO is genetically heterogeneous, and is associated with mutations in Exostosin-1 (EXT1) or Exostosin-2 (EXT2), both tumor-suppressor genes of the EXT gene family. All members of this multigene family encode glycosyltransferases involved in the adhesion and/or polymerization of heparin sulfate (HS) chains at HS proteoglycans (HSPGs). HSPGs have been shown to play a role in the diffusion of Ihh, thereby regulating chondrocyte proliferation and differentiation. EXT1 is located at 8q24.11-q24.13, and comprises 11 exons, whereas the 16 exon EXT2 is located at 11p12-p11. To date, an EXT1 or EXT2 mutation is detected in 70-95% of affected individuals. EXT1 mutations are detected in +/-65% of cases, versus +/-35% EXT2 mutations in MO patient cohorts. Inactivating mutations (nonsense, frame shift, and splice-site mutations) represent the majority of MO causing mutations (75-80%). In this article, the clinical aspects and molecular genetics of EXT1 and EXT2 are reviewed together with 895 variants in MO patients. An overview of the reported variants is provided by the online Multiple Osteochondromas Mutation Database (http://medgen.ua.ac.be/LOVD).
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Affiliation(s)
- Ivy Jennes
- Department of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
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31
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Heinritz W, Hüffmeier U, Strenge S, Miterski B, Zweier C, Leinung S, Bohring A, Mitulla B, Peters U, Froster UG. New Mutations ofEXT1andEXT2Genes in German Patients with Multiple Osteochondromas. Ann Hum Genet 2009; 73:283-91. [DOI: 10.1111/j.1469-1809.2009.00508.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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32
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Kojima H, Wada T, Seki H, Kubota T, Wakui K, Fukushima Y. One Third of Japanese Patients with Multiple Osteochondromas May Have Mutations in Genes Other Than EXT1 or EXT2. ACTA ACUST UNITED AC 2008; 12:557-61. [DOI: 10.1089/gte.2008.0048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hirofumi Kojima
- Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
- Department of Orthopedic Surgery, Inariyama Medical and Welfare Center, Chikuma, Japan
| | - Takahito Wada
- Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Hiroshi Seki
- Department of Orthopedic Surgery, Shinshu University School of Medicine, Matsumoto, Japan
| | - Takeo Kubota
- Epigenetic Medicine, University of Yamanashi, Faculty of Medicine, Chuo, Japan
| | - Keiko Wakui
- Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yoshimitsu Fukushima
- Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
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33
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Pannier S, Legeai-Mallet L. Hereditary multiple exostoses and enchondromatosis. Best Pract Res Clin Rheumatol 2008; 22:45-54. [PMID: 18328980 DOI: 10.1016/j.berh.2007.12.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Hereditary multiple exostoses (HME) is an autosomal-dominant disorder characterized by the development of benign tumours, multiple osteochondromas (exostoses), growing outward from the metaphyses of long bones. Birth prevalence is estimated to be one in 50,000, and the severity of the disease is variable. Osteochondromas may cause complications including pain, deformities and shortening of the long bones, restricted motion of joints, nerve or blood vessel compression, and malignant transformation (5% of cases) in adulthood. HME is a genetically heterogeneous disorder and is associated with mutations in EXT1 or EXT2 genes, which are both tumour suppressor genes. EXT genes encode glycosyltransferases, termed 'exostosins', which are involved in the biosynthesis of heparan sulphate. Enchondromatosis (or Ollier disease) is characterized by the presence of intra-osseous benign cartilaginous tumours. The estimated prevalence of the disease is one in 100,000. An asymmetrical distribution of cartilage lesions is observed in the disease. The number, size and location of the enchondromas can be extremely variable between patients. Clinical problems caused by enchondromas include skeletal deformities, limb length discrepancy, pain and the potential risk for malignant change to chondrosarcoma (20-50% of cases). The condition in which multiple enchondromas is associated with haemangiomas is known as 'Maffucci syndrome'. Ollier disease and Maffucci syndrome are not usually inherited disorders.
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Affiliation(s)
- Stéphanie Pannier
- INSERM U781, Hôpital Necker, Enfants Malades, 149 rue de Sèvres, 75015 Paris, France
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34
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Tan LJ, Liu YZ, Xiao P, Yang F, Tang ZH, Liu PY, Recker RR, Deng HW. Evidence for major pleiotropic effects on bone size variation from a principal component analysis of 451 Caucasian families. Acta Pharmacol Sin 2008; 29:745-51. [PMID: 18501122 DOI: 10.1111/j.1745-7254.2008.00806.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIM To identify pleiotropic quantitative trait loci (QTL) influencing bone size (BS) at different skeletal sites in Caucasians. METHODS In a sample containing 3899 Caucasians from 451 pedigrees, 410 microsatellite markers spaced approximately 8.9 cM apart across the human genome were genotyped. Phenotypical and genetic correlations of BS at lumbar spine, hip (femoral neck, trochanter, and intertrochanter regions), and wrist (ultradistal, mid-distal, and one-third distal sites) were determined using bivariate quantitative genetic analysis. A principal component analysis (PCA) was performed to obtain principal component (PC) factors that were then subjected to variance components linkage analysis to identify regions linked to the PC. RESULTS Genetic correlations of BS at different skeletal sites ranged from 0.40 to 0.79 (P<0.001). The PCA yielded a PC named PCtotal, which explained up to 76% of the total (co)variation of all the BS at the 7 skeletal sites for the whole sample. We identified a QTL influencing the BS of multiple skeletal sites on chromosome 7 at 140 cM [logarithm of odds (LOD)=2.85] in the overall sample. Sex-specific evidence for linkage was observed on chromosome 11 at 53 cM (LOD =2.82) in the male-only data subset. CONCLUSION Our study identified several genomic regions that may have pleiotropic effects on different skeletal sites. These regions may contain genes that play a critical role in overall bone development and osteoporosis at multiple skeletal sites, hence are biologically and clinically important.
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Affiliation(s)
- Li-jun Tan
- Laboratory of Molecular and Statistical Genetics, Hunan Normal University, Changsha 410081, China
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35
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Genetic analysis of hereditary multiple exostoses in Tunisian families: a novel frame-shift mutation in the EXT1 gene. Mol Biol Rep 2008; 36:661-7. [DOI: 10.1007/s11033-008-9226-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Accepted: 03/05/2008] [Indexed: 11/26/2022]
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36
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Leube B, Hardt K, Portier S, Westhoff B, Jäger M, Krauspe R, Royer-Pokora B. Ulna/Height Ratio as Clinical Parameter SeparatingEXT1fromEXT2Families? ACTA ACUST UNITED AC 2008; 12:129-33. [DOI: 10.1089/gte.2007.0070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Barbara Leube
- Institute of Human Genetics, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
| | - Karin Hardt
- Institute of Human Genetics, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
| | - Sebastian Portier
- Department of Orthopaedics, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
| | - Bettina Westhoff
- Department of Orthopaedics, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
| | - Marcus Jäger
- Department of Orthopaedics, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
| | - Rüdiger Krauspe
- Department of Orthopaedics, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
| | - Brigitte Royer-Pokora
- Institute of Human Genetics, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
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37
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Abstract
Multiple osteochondromas (MO) is characterised by development of two or more cartilage capped bony outgrowths (osteochondromas) of the long bones. The prevalence is estimated at 1:50,000, and it seems to be higher in males (male-to-female ratio 1.5:1). Osteochondromas develop and increase in size in the first decade of life, ceasing to grow when the growth plates close at puberty. They are pedunculated or sessile (broad base) and can vary widely in size. The number of osteochondromas may vary significantly within and between families, the mean number of locations is 15-18. The majority are asymptomatic and located in bones that develop from cartilage, especially the long bones of the extremities, predominantly around the knee. The facial bones are not affected. Osteochondromas may cause pain, functional problems and deformities, especially of the forearm, that may be reason for surgical removal. The most important complication is malignant transformation of osteochondroma towards secondary peripheral chondrosarcoma, which is estimated to occur in 0.5-5%. MO is an autosomal dominant disorder and is genetically heterogeneous. In almost 90% of MO patients germline mutations in the tumour suppressor genes EXT1 or EXT2 are found. The EXT genes encode glycosyltransferases, catalyzing heparan sulphate polymerization. The diagnosis is based on radiological and clinical documentation, supplemented with, if available, histological evaluation of osteochondromas. If the exact mutation is known antenatal diagnosis is technically possible. MO should be distinguished from metachondromatosis, dysplasia epiphysealis hemimelica and Ollier disease. Osteochondromas are benign lesions and do not affect life expectancy. Management includes removal of osteochondromas when they give complaints. Removed osteochondromas should be examined for malignant transformation towards secondary peripheral chondrosarcoma. Patients should be well instructed and regular follow-up for early detection of malignancy seems justified. For secondary peripheral chondrosarcoma, en-bloc resection of the lesion and its pseudocapsule with tumour-free margins, preferably in a bone tumour referral centre, should be performed.
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Affiliation(s)
- Judith V M G Bovée
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands.
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38
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Jennes I, Entius MM, Van Hul E, Parra A, Sangiorgi L, Wuyts W. Mutation screening of EXT1 and EXT2 by denaturing high-performance liquid chromatography, direct sequencing analysis, fluorescence in situ hybridization, and a new multiplex ligation-dependent probe amplification probe set in patients with multiple osteochondromas. J Mol Diagn 2007; 10:85-92. [PMID: 18165274 DOI: 10.2353/jmoldx.2008.070086] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multiple osteochondromas (MO) is an autosomal-dominant skeletal disorder characterized by the formation of multiple cartilage-capped protuberances. MO is genetically heterogeneous and is associated with mutations in the EXT1 and EXT2 genes. In this study we describe extensive mutation screening in a set of 63 patients with clinical and radiographical diagnosis of MO. Denaturing high-performance liquid chromatography analysis revealed mutations in 43 patients. Additional deletion analysis by fluorescence in situ hybridization and a newly developed multiplex ligation-dependent probe amplification probe set identified one patient with an intragenic EXT1 translocation, three patients with a partial EXT1 deletion, and one patient with a partial EXT2 deletion. Thirty-six patients harbored an EXT1 mutation (57%), and 12 had an EXT2 mutation (19%). We show that our optimized denaturing high-performance liquid chromatography/sequencing/multiplex ligation-dependent probe amplification protocol represents a reliable and highly sensitive diagnostic strategy for mutation screening in MO patients. Clinical analysis showed no clear genotype-phenotype correlation in our cohort of MO patients.
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Affiliation(s)
- Ivy Jennes
- Department of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
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