1
|
Borovikov A, Marakhonov A, Murtazina A, Davydenko K, Filatova A, Galeeva N, Kadnikova V, Ogorodova N, Gorodilova D, Kanivets I, Pyankov D, Zherdev K, Petel’guzov A, Zubkov P, Polyakov A, Shchagina O, Skoblov M. Cases report: Mosaic structural variants of the EXT1 gene in previously genetically unconfirmed multiple osteochondromas. Front Genet 2024; 15:1435493. [PMID: 39192890 PMCID: PMC11347319 DOI: 10.3389/fgene.2024.1435493] [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: 05/20/2024] [Accepted: 07/26/2024] [Indexed: 08/29/2024] Open
Abstract
Multiple osteochondromas (MO) is a rare autosomal dominant skeletal disorder characterized by the development of multiple benign tumors known as osteochondromas. The condition is predominantly caused by loss-of-function variants in the EXT1 or EXT2 genes, facilitating relatively precise clinical diagnosis through established diagnostic criteria. Despite this, a notable percentage of MO cases (10%-20%) remains unresolved after sequencing coding regions and copy number analysis of both genes. In our study, we identified mosaic structural variants in two patients who initially yielded negative results on standard genetic analysis for MO. Specifically, mosaic deletions affecting exons 8-11 and exons 2-11 in the EXT1 gene were detected. RNA analysis was performed in one case, while both cases underwent genome sequencing. To date, only six mosaic copy number variations have been reported in association with MO, representing a minority among known variants in both genes. Our report provides a detailed analysis of these findings, highlighting the significance of advanced genetic testing techniques in detecting mosaic variants in the EXT1/2 genes.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Ilya Kanivets
- Genomed, Moscow, Russia
- Federal State Budgetary Educational Institution, Further Professional Education, Russian Medical Academy of Continuous Professional Education, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | | | - Konstantin Zherdev
- National Medical Research Center of Children’s Health, Moscow, Russia
- Department of Pediatric Surgery and Urology-Andrology, I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | | | - Pavel Zubkov
- National Medical Research Center of Children’s Health, Moscow, Russia
| | | | | | | |
Collapse
|
2
|
Shaikh U, Shah P, Jones V, Ramos-Rodriguez AJ, Sriharan A, Loo E, Khan WA, Simmons B, Cloutier JM. Subungual melanoma with cartilaginous differentiation: Molecular insights. J Cutan Pathol 2024; 51:576-582. [PMID: 38666479 DOI: 10.1111/cup.14630] [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: 11/20/2023] [Revised: 02/02/2024] [Accepted: 04/15/2024] [Indexed: 07/09/2024]
Abstract
Melanoma's rare capacity to undergo heterologous differentiation can create significant diagnostic challenges. The molecular mechanisms underlying this phenomenon are not well understood. We present an unusual case of subungual melanoma exhibiting extensive cartilaginous differentiation and provide insights into its molecular and cytogenomic features. Histopathologically, the tumor was predominantly composed of nodules of malignant cartilage in association with a smaller population of nested epithelioid to rhabdoid cells. Immunohistochemically, the tumor cells in both components were positive for S100, SOX10, and PRAME, and were negative for Melan-A and HMB-45. Molecular analysis by whole exome DNA sequence did not detect any pathogenic variants in genes commonly implicated in melanoma. Additional analysis by SNP chromosomal microarray revealed a complex genome characterized by numerous chromosomal losses and gains, including a homozygous deletion of the CDKN2A locus and a heterozygous deletion of the locus containing EXT2, a tumor suppressor implicated in hereditary multiple osteochondromas and secondary chondrosarcomas. This case underscores the importance of recognizing cartilaginous differentiation as a rare manifestation of melanoma, particularly at subungual sites, and suggests that at least some of these melanomas may be driven by non-canonical molecular pathways.
Collapse
Affiliation(s)
- Umayr Shaikh
- School of Medicine, Georgetown University, Washington, DC, USA
| | - Payal Shah
- Department of Dermatology, Dartmouth Health, Lebanon, New Hampshire, USA
| | - Victoria Jones
- Department of Pathology and Laboratory Medicine, One Medical Center Drive, Dartmouth Health, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Alvaro J Ramos-Rodriguez
- Department of Pathology and Laboratory Medicine, One Medical Center Drive, Dartmouth Health, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Aravindhan Sriharan
- Department of Pathology and Laboratory Medicine, One Medical Center Drive, Dartmouth Health, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Eric Loo
- Department of Pathology and Laboratory Medicine, One Medical Center Drive, Dartmouth Health, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Wahab A Khan
- Department of Pathology and Laboratory Medicine, One Medical Center Drive, Dartmouth Health, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Brian Simmons
- Department of Dermatology, Dartmouth Health, Lebanon, New Hampshire, USA
| | - Jeffrey M Cloutier
- Department of Pathology and Laboratory Medicine, One Medical Center Drive, Dartmouth Health, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| |
Collapse
|
3
|
Güneş N, Uludağ Alkaya D, Toylu A, Özüdoğru P, Çifçi Sunamak E, Şeker A, Demir B, Kuruğoğlu S, Mıhçı E, Tüysüz B. Phenotypic and Molecular Spectrum of a Turkish Cohort with Hereditary Multiple Osteochondromas. Turk Arch Pediatr 2023; 58:376-381. [PMID: 37317574 PMCID: PMC10440955 DOI: 10.5152/turkarchpediatr.2023.23011] [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: 01/13/2023] [Accepted: 03/28/2023] [Indexed: 06/16/2023]
Abstract
OBJECTIVE Hereditary multiple osteochondromas is an autosomal dominant disorder caused by heterozygous pathogenic variants in EXT1 or EXT2. We aimed to evaluate the clinical and molecular findings of a Turkish cohort with hereditary multiple osteochondroma. MATERIALS AND METHODS Thirty-two patients aged 1.3-49.6 years from 22 families were enrolled. Genetic analyses were made by EXT1 and/or EXT2 sequencing and chromosomal microarray analyses. RESULTS We found 17 intragenic pathogenic variants in EXT1 (13/17) and EXT2 (4/17), 12 of which are novel. Four probands had EXT1 deletions, including 2 patients with partial EXT1 microdeletions involving exons 2-11 and 5-11, and 2 patients with whole-gene deletions. In 21 variants, the frequency of truncating and missense variants was 76.1% and 23.8%, respectively. Two families had no detectable variants in EXT1 and EXT2. All patients had multiple osteochondromas at the long bones, mainly at the tibia, forearm, femur, and humerus. Bowing deformity of the forearms (9/32) and the lower extremities (2/32), and scoliosis (6/32) were observed. The clinical severity was not different between patients with EXT1 or EXT2 variants. One patient with an EXT2 variant and another with an EXT1 microdeletion had the most severe phenotype with class III disease. Four patients with no EXT1 or EXT2 variants had milder phenotypes. Intrafamilial variability in disease severity was not observed. CONCLUSION We report a hereditary multiple osteochondroma cohort with clinical and molecular data including 12 novel intragenic variants in EXT1 or EXT2, and 4 microdeletions involving EXT1. Taken together, our data expand the existing knowledge of the phenotype-genotype spectrum in hereditary multiple osteochondroma.
Collapse
Affiliation(s)
- Nilay Güneş
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, İstanbul, Turkey
| | - Dilek Uludağ Alkaya
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, İstanbul, Turkey
| | - Aslı Toylu
- Department of Medical Genetics, Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Püren Özüdoğru
- Department of Pediatric Genetics, Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Evrim Çifçi Sunamak
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, İstanbul, Turkey
| | - Ali Şeker
- Department of Orthopedics and Traumatology, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Istanbul, Turkey
| | - Bilal Demir
- Department of Orthopedics and Traumatology, Metin Sabancı Baltalimanı Bone Diseases Training and Research Center, Health Sciences University, İstanbul, Turkey
| | - Sebuh Kuruğoğlu
- Department of Radiology, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, İstanbul, Turkey
| | - Ercan Mıhçı
- Department of Pediatric Genetics, Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, İstanbul, Turkey
| |
Collapse
|
4
|
Güneş N, Usluer E, Yüksel Ülker A, Uludağ Alkaya D, Çifçi Sunamak E, Celep Eyüpoğlu F, Oya Uyguner Z, Tüysüz B, Tuysuz B. The Clinical and Molecular Spectrum of Trichorhinophalangeal Syndrome Types I and II in a Turkish Cohort Involving 22 Patients. Turk Arch Pediatr 2023; 58:98-104. [PMID: 36598218 PMCID: PMC9885788 DOI: 10.5152/turkarchpediatr.2022.22223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Trichorhinophalangeal syndrome is a rare autosomal dominant disorder characterized by distinctive craniofacial and skeletal abnormalities. This study aimed to delineate the trichorhinophalangeal syndrome phenotype and to compare the clinical and molecular findings between trichorhinophalangeal syndrome types I and II. MATERIALS AND METHODS A total of 22 trichorhinophalangeal syndrome patients aged 0.9-45 years from 17 families were enrolled. Nineteen patients were diagnosed with trichorhin ophalangeal syndrome I and 3 with trichorhinophalangeal syndrome II. Genetic analyses were made by TRPS1 sequencing and/or chromosomal microarray analyses. RESULTS A novel frameshift variant (c.531_532del), a known missense variant, and whole-gene deletions were the pathogenic TRPS1 variants detected in trichorhinophalangeal syndrome I. Three trichorhinophalangeal syndrome II patients had large deletions with variable breakpoints involving the TRPS1-EXT1 interval. All patients had the typical craniofacial findings of trichorhinophalangeal syndrome such as a pear-shaped nose, long philtrum, and thin upper lip, as well as cone-shaped epiphyses. Sparse hair and eyebrows (20/22), short metacarpals and metatarsals (20/22), and small hands (19/22) were common. While craniofacial and limb abnormalities were similar in trichorhinophalangeal syndrome I and II, 3 of 19 trichorhinophal angeal syndrome I patients had mild, and 2 of 3 trichorhinophalangeal syndrome II patients had severe intellectual disability. Three trichorhinophalangeal syndrome II patients including the patient with the EXT1 deletion beginning from exon 2 had exostoses. In trichorhinophal angeal syndrome II, although microdeletion sizes and facial or skeletal features were not correlated, patients with larger deletions had severe intellectual disability. CONCLUSION This study has expanded the existing knowledge on the phenotype-genotype spectrum in trichorhinophalangeal syndrome. We suggest including the EXT1 gene partially in the minimal critical region for trichorhinophalangeal syndrome II.
Collapse
Affiliation(s)
- Nilay Güneş
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | - Esra Usluer
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | - Aylin Yüksel Ülker
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | - Dilek Uludağ Alkaya
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | - Evrim Çifçi Sunamak
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey
| | | | - Zehra Oya Uyguner
- Department of Medical Genetics, İstanbul University, İstanbul Faculty of Medicine, İstanbul, Turkey
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, İstanbul University-Cerrahpaşa, Cerrahpaşa Medical Faculty, Istanbul, Turkey,Corresponding author:Beyhan Tüysüz ✉
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Gómez-Flores-Ramos L, Barraza-Arellano AL, Mohar A, Trujillo-Martínez M, Grimaldo L, Ortiz-Lopez R, Treviño V. Germline Variants in Cancer Genes from Young Breast Cancer Mexican Patients. Cancers (Basel) 2022; 14:cancers14071647. [PMID: 35406420 PMCID: PMC8997148 DOI: 10.3390/cancers14071647] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/03/2022] [Accepted: 03/18/2022] [Indexed: 02/05/2023] Open
Abstract
Breast cancer (BC) is one of the most frequent cancer types in women worldwide. About 7% is diagnosed in young women (YBC) less than 40 years old. In Mexico, however, YBC reaches 15% suggesting a higher genetic susceptibility. There have been some reports of germline variants in YBC across the world. However, there is only one report from a Mexican population, which is not restricted by age and limited to a panel of 143 genes resulting in 15% of patients carrying putatively pathogenic variants. Nevertheless, expanding the analysis to whole exome involves using more complex tools to determine which genes and variants could be pathogenic. We used germline whole exome sequencing combined with the PeCanPie tool to analyze exome variants in 115 YBC patients. Our results showed that we were able to identify 49 high likely pathogenic variants involving 40 genes on 34% of patients. We noted many genes already reported in BC and YBC worldwide, such as BRCA1, BRCA2, ATM, CHEK2, PALB2, and POLQ, but also others not commonly reported in YBC in Latin America, such as CLTCL1, DDX3X, ERCC6, FANCE, and NFKBIE. We show further supporting and controversial evidence for some of these genes. We conclude that exome sequencing combined with robust annotation tools and further analysis, can identify more genes and more patients affected by germline mutations in cancer.
Collapse
Affiliation(s)
- Liliana Gómez-Flores-Ramos
- CONACYT/Center for Population Health Research, National Institute of Public Health, Universidad No. 655, Cuernavaca 62100, Morelos, Mexico; (L.G.-F.-R.); (L.G.)
| | - Angélica Leticia Barraza-Arellano
- School of Medicine, Tecnologico de Monterrey, Morones Prieto Av 3000, Los Doctores, Monterrey 64710, Nuevo Leon, Mexico; (A.L.B.-A.); (R.O.-L.)
| | - Alejandro Mohar
- Unidad de Investigación Biomédica en Cáncer, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Dirección de Investigación, Instituto Nacional de Cancerología, Av. San Fernando #22, Col. Sección XVI, Delegación Tlalpan, Mexico City 14080, Mexico;
| | - Miguel Trujillo-Martínez
- Instituto Mexicano del Seguro Social, Hospital General de Zona con Medicina Familiar No. 7, Cuautla 62780, Morelos, Mexico;
| | - Lizbeth Grimaldo
- CONACYT/Center for Population Health Research, National Institute of Public Health, Universidad No. 655, Cuernavaca 62100, Morelos, Mexico; (L.G.-F.-R.); (L.G.)
| | - Rocío Ortiz-Lopez
- School of Medicine, Tecnologico de Monterrey, Morones Prieto Av 3000, Los Doctores, Monterrey 64710, Nuevo Leon, Mexico; (A.L.B.-A.); (R.O.-L.)
- The Institute for Obesity Research, Tecnologico de Monterrey, Eugenio Garza Sada Av 2501, Monterrey 64849, Nuevo Leon, Mexico
| | - Víctor Treviño
- School of Medicine, Tecnologico de Monterrey, Morones Prieto Av 3000, Los Doctores, Monterrey 64710, Nuevo Leon, Mexico; (A.L.B.-A.); (R.O.-L.)
- The Institute for Obesity Research, Tecnologico de Monterrey, Eugenio Garza Sada Av 2501, Monterrey 64849, Nuevo Leon, Mexico
- Correspondence:
| |
Collapse
|
7
|
Bukowska-Olech E, Trzebiatowska W, Czech W, Drzymała O, Frąk P, Klarowski F, Kłusek P, Szwajkowska A, Jamsheer A. Hereditary Multiple Exostoses-A Review of the Molecular Background, Diagnostics, and Potential Therapeutic Strategies. Front Genet 2021; 12:759129. [PMID: 34956317 PMCID: PMC8704583 DOI: 10.3389/fgene.2021.759129] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 11/08/2021] [Indexed: 11/17/2022] Open
Abstract
Hereditary multiple exostoses (HMEs) syndrome, also known as multiple osteochondromas, represents a rare and severe human skeletal disorder. The disease is characterized by multiple benign cartilage-capped bony outgrowths, termed exostoses or osteochondromas, that locate most commonly in the juxta-epiphyseal portions of long bones. Affected individuals usually complain of persistent pain caused by the pressure on neighboring tissues, disturbance of blood circulation, or rarely by spinal cord compression. However, the most severe complication of this condition is malignant transformation into chondrosarcoma, occurring in up to 3.9% of HMEs patients. The disease results mainly from heterozygous loss-of-function alterations in the EXT1 or EXT2 genes, encoding Golgi-associated glycosyltransferases, responsible for heparan sulfate biosynthesis. Some of the patients with HMEs do not carry pathogenic variants in those genes, hence the presence of somatic mutations, deep intronic variants, or another genes/loci is suggested. This review presents the systematic analysis of current cellular and molecular concepts of HMEs along with clinical characteristics, clinical and molecular diagnostic methods, differential diagnosis, and potential treatment options.
Collapse
Affiliation(s)
| | | | - Wiktor Czech
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Olga Drzymała
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Piotr Frąk
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Piotr Kłusek
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Anna Szwajkowska
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Aleksander Jamsheer
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland.,Centers for Medical Genetics GENESIS, Poznan, Poland
| |
Collapse
|
8
|
Mutational Analysis of EXT1in a Chinese Family Affected by Hereditary Multiple Osteochondroma. BIOMED RESEARCH INTERNATIONAL 2021; 2021:8888948. [PMID: 34409107 PMCID: PMC8367584 DOI: 10.1155/2021/8888948] [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: 09/17/2020] [Accepted: 07/08/2021] [Indexed: 11/17/2022]
Abstract
Objectives To discuss the mutational features and their relationships with disease in a family with hereditary multiple osteochondroma (HMO) from Guangxi Province (GXBB-1 family), China. Methods Genomic DNA and total mRNA were extracted from peripheral blood cells of GXBB-1 family members. Whole elements of the EXT1gene and its transcript, including exons, introns, exon-intron boundaries, and coding sequence (CDS) clones, were amplified and sequenced. Allele-specific PCR was used to confirm the position and type of mutation. Results All patients from the GXBB-1 family harbored the cosegregating heterozygous c.1056+1G>A mutation located in EXT1at an exon-intron boundary. Another three single-nucleotide polymorphisms (SNPs) were also detected in the patients, including IVS2+1G>A in intron 2, c.1844 T>C [p.Pro (CCT) 614Pro (CCC)] in exon 3, and c.2534G>A [p.Glu (GAG) 844Glu (GAA)] in exon 9. The latter two SNPs were synonymous variations. Conclusions The heterozygous c.1056+1G>A mutation cosegregated with the phenotype, indicating that it is a pathogenic mutation in the GXBB-1 family. This mutation is reported for the first time in Chinese HMO patients. IVS2+1G>A and c.2534G>A have no relationship with the occurrence of disease. However, c.1844 T>C and c.1056+1G>A are linked, and their interaction needs to be further studied. c.1844T>C is a new SNP that has not been reported internationally.
Collapse
|
9
|
Tong Y, Luo J, Zhang Y, Hong Z, Cao L, Chen X, Chen J, Bi Q. Novel Mutations in Chinese Patients with Multiple Osteochondromas Identified Using Whole Exome Sequencing. Genet Test Mol Biomarkers 2021; 25:361-367. [PMID: 34003695 DOI: 10.1089/gtmb.2020.0317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background: Multiple osteochondromas (MO) are an autosomal-dominant disease characterized by the growth of multiple cartilage-capped prominences in the growth plate region of the metaphysis in long and flat bones. Materials and Methods: To detect genetic mutations related to MO, a three-generation Chinese family with MO was evaluated using whole exome sequencing for mutation screening. The candidate pathogenic mutation was validated by Sanger sequencing. Results: A novel frameshift (NM_000401.3:c.1321del:p.Leu441TrpfsTer28) in exon 8 of the exotosin 2 (EXT2) gene was identified in two affected individuals. Codons 441 and 468 in the EXT2 gene are highly conserved among vertebrates as demonstrated by multiple sequence alignment. The c.1321 del C resulted in an amino acid change at codon 441, which generated a premature stop codon at position 468, causing complete loss of the glycosyltransferase domain. Conclusions: A novel frameshift mutation c.1321delC detected in the EXT2 gene may help in prenatal genetic screening and early diagnosis of MO.
Collapse
Affiliation(s)
- Yu Tong
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.,Department of Orthopedic Surgery, People's Hospital of Hangzhou Medical College, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| | - Junchao Luo
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yin Zhang
- Graduate Department, Bengbu Medical College, Bengbu, China
| | - Zheping Hong
- Department of Orthopedic Surgery, People's Hospital of Hangzhou Medical College, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| | - Li Cao
- Department of Orthopedic Surgery, People's Hospital of Hangzhou Medical College, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| | - Xinji Chen
- Department of Orthopedic Surgery, People's Hospital of Hangzhou Medical College, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| | - Jihang Chen
- Department of Orthopedic Surgery, People's Hospital of Hangzhou Medical College, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| | - Qing Bi
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.,Department of Orthopedic Surgery, People's Hospital of Hangzhou Medical College, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| |
Collapse
|
10
|
Wang CY, Yu F, Jin JY, He JQ, Fan LL, Tang JY, Xiang R. Identification of Two Novel Frameshift Mutations in Exostosin 1 in Two Families with Multiple Osteochondromas. Mol Syndromol 2021; 12:96-100. [PMID: 34012378 DOI: 10.1159/000512856] [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: 03/10/2020] [Accepted: 11/05/2020] [Indexed: 11/19/2022] Open
Abstract
Multiple osteochondromas (MO) is an autosomal dominant hereditary disorder, which typically manifests as skeletal dysplasia, mainly involving long bones and knees, ankles, elbows, wrists, shoulders, and pelvis. Previous studies have demonstrated that mutations in exostosin glycosyl transferase-1 (EXT1) and exostosin glycosyl transferase-2 (EXT2) were the main cause of MO. In this study, we enrolled 2 families with MO. Sanger sequencing revealed 2 novel frameshift mutations - c.1432_1433insCCCCCCT; p.Lys479Profs*44 and c.1431_1431delC; p.S478PfsX10 - in the EXT1 gene detected in 2 families, respectively. Both novel mutations, located in the conserved domain of EXT1 and predicted to be disease causing by informatics programs, were absent in our 200 control cohorts and other public databases. Our study expanded the spectrum of EXT1 mutations and contributed to genetic diagnosis and counseling of patients with MO.
Collapse
Affiliation(s)
- Chen-Yu Wang
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, China.,Department of Orthopedics, Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China
| | - Fang Yu
- Department of Orthopedics, Xiangya Hospital of Central South University, Changsha, China
| | - Jie-Yuan Jin
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, China
| | - Ji-Qiang He
- Department of Orthopedics, Xiangya Hospital of Central South University, Changsha, China
| | - Liang-Liang Fan
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, China.,Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China
| | - Ju-Yu Tang
- Department of Orthopedics, Xiangya Hospital of Central South University, Changsha, China
| | - Rong Xiang
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha, China.,Department of Orthopedics, Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Animal Models for Human Diseases, School of Life Sciences, Central South University, Changsha, China
| |
Collapse
|
11
|
Mohaidat Z, Bodoor K, Almomani R, Alorjani M, Awwad MA, Bany-Khalaf A, Al-Batayneh K. Hereditary multiple osteochondromas in Jordanian patients: Mutational and immunohistochemical analysis of EXT1 and EXT2 genes. Oncol Lett 2020; 21:151. [PMID: 33552269 PMCID: PMC7798038 DOI: 10.3892/ol.2020.12412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 11/26/2020] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to investigate the molecular characteristics of hereditary multiple osteochondromas (HMO) in a subset of Jordanian patients with a focus on the genetic variants of exostosin (EXT1)/(EXT2) and their protein expression. Patients with HMO and their family members were included. Recorded clinical characteristics included age, sex, tumors number and location, joint deformities and associated functional limitations. Mutational analysis of EXT1 and EXT2 exonic regions was performed. Immunohistochemical staining for EXT1 and EXT2 was performed manually using two different commercially available rabbit anti-human EXT1 and EXT2 antibodies. A total of 16 patients with HMO from nine unrelated families were included, with a mean age of 13.9 years. A total of 75% (12/16) of the patients were male and (69%) (11/16) had a mild disease (class I). EXT mutation analysis revealed only EXT1 gene mutations in 13 patients. Seven variants were detected, among which three were novel: c.1019G>A, p. (Arg340His), c.962+1G>A and c.1469del, p. (Leu490Argfs*9). Of the 16 patients, 3 did not harbor any mutations for either EXT1 or EXT2. Immunohistochemical examination revealed decreased expression of EXT1 protein in all patients with EXT1 mutation. Surprisingly, EXT2 protein was not detected in these patients, although none had EXT2 mutations. The majority of Jordanian patients with HMO, who may represent an ethnic group that is infrequently investigated, were males and had a mild clinical disease course; whereas most patients with EXT1 gene mutations were not necessarily associated with a severe clinical disease course. The role of EXT2 gene remains a subject of debate, since patients with EXT1 mutations alone did not express the non-mutated EXT2 gene.
Collapse
Affiliation(s)
- Ziyad Mohaidat
- Orthopedic Division, Special Surgery Department, Faculty of Medicine, Jordan University of Science and Technology, King Abdullah University Hospital, Irbid 22110, Jordan
| | - Khaldon Bodoor
- Department of Applied Biology, Faculty of Science, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Rowida Almomani
- Department of Laboratory Medical Sciences, Faculty of Science, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Mohammed Alorjani
- Department of Pathology, Faculty of Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Mohammad-Akram Awwad
- Department of Clinical Sciences, Faculty of Medicine, Yarmouk University, Irbid 21110, Jordan
| | - Audai Bany-Khalaf
- Orthopedic Division, Special Surgery Department, Faculty of Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Khalid Al-Batayneh
- Department of Biology, Faculty of Sciences, Yarmouk University, Irbid 21110, Jordan
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Wu D, Huo C, Jiang S, Huang Y, Fang X, Liu J, Yang M, Ren J, Xu B, Liu Y. Exostosin1 as a novel prognostic and predictive biomarker for squamous cell lung carcinoma: A study based on bioinformatics analysis. Cancer Med 2020; 10:2787-2801. [PMID: 33314711 PMCID: PMC8026939 DOI: 10.1002/cam4.3643] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 11/04/2020] [Accepted: 11/08/2020] [Indexed: 12/13/2022] Open
Abstract
The exostosin (EXT) protein family is involved in diverse human diseases. However, the expression and prognostic value of EXT genes in human lung squamous cell carcinoma (LUSC) is not well understood. In this study, we analyzed the association between expression of EXT1 and EXT2 genes and survival in patients with LUSC using bioinformatics resources such as Oncomine and The Cancer Genome Atlas (TCGA) databases, the Gene Expression Profiling Interactive Analysis (GEPIA) server and Kaplan–Meier plotter. Furthermore, regulatory microRNAs (miRNAs) were predicted for EXT1 and used to establish a potential miRNA‐messenger RNA (mRNA) regulation network for LUSC using the ENCORI platform. We observed that EXT1 and EXT2 expression levels were higher in LUSC than those in normal tissues. However, only EXT1 expression was significantly associated with poor overall survival (OS) in LUSC patients. Functional annotation enrichment analysis showed that genes co‐expressed with the EXT1 gene were enriched in biological processes such as cell adhesion and migration, and KEGG pathways such as extracellular matrix receptor interactions, complement and coagulation cascades, and cell death. Furthermore, three miRNAs, hsa‐mir‐190a‐5p, hsa‐mir‐195‐5p, and hsa‐mir‐490‐3p, were identified to be potentially involved in the regulation of EXT1. In summary, we identified EXT1 expression as a novel potential prognostic marker for human LUSC and the regulatory miRNAs that could possibly contribute to the prognosis of the disease.
Collapse
Affiliation(s)
- Disheng Wu
- Guangdong Key Laboratory for Research and Development of Natural Drugs, Department of Pharmacology, Marine Medicine Research Institute, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Chao Huo
- Guangdong Key Laboratory for Research and Development of Natural Drugs, Department of Pharmacology, Marine Medicine Research Institute, Guangdong Medical University, Zhanjiang, Guangdong, China.,Department of Anus and Intestines, Shenzhen Nanshan District People's Hospital, Shenzhen, Guangdong, China
| | - Siyu Jiang
- Guangdong Key Laboratory for Research and Development of Natural Drugs, Department of Pharmacology, Marine Medicine Research Institute, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Yanxia Huang
- Department of Pharmacy, The Third People's Hospital of Shantou, Shantou, Guangdong, China
| | - Xuehong Fang
- Guangdong Key Laboratory for Research and Development of Natural Drugs, Department of Pharmacology, Marine Medicine Research Institute, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Jun Liu
- Shenzhen Ritzcon Biological Technology Co., Ltd., Shenzhen, Guangdong, China
| | - Min Yang
- Shenzhen Ritzcon Biological Technology Co., Ltd., Shenzhen, Guangdong, China
| | - Jianwei Ren
- Shenzhen Ritzcon Biological Technology Co., Ltd., Shenzhen, Guangdong, China
| | - Bilian Xu
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Yi Liu
- Guangdong Key Laboratory for Research and Development of Natural Drugs, Department of Pharmacology, Marine Medicine Research Institute, Guangdong Medical University, Zhanjiang, Guangdong, China
| |
Collapse
|
14
|
Li Y, Lin X, Zhu M, Xun F, Li J, Yuan Z, Liu Y, Xu H. A mutation in SLC20A2 (c.C1849T) promotes proliferation while inhibiting hypertrophic differentiation in ATDC5 chondrocytes. Bone Joint Res 2020; 9:751-760. [PMID: 33135420 PMCID: PMC7649514 DOI: 10.1302/2046-3758.911.bjr-2020-0112.r1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
AIMS This study aimed to investigate the effect of solute carrier family 20 member 2 (SLC20A2) gene mutation (identified from a hereditary multiple exostoses family) on chondrocyte proliferation and differentiation. METHODS ATDC5 chondrocytes were cultured in insulin-transferrin-selenium medium to induce differentiation. Cells were transfected with pcDNA3.0 plasmids with either a wild-type (WT) or mutated (MUT) SLC20A2 gene. The inorganic phosphate (Pi) concentration in the medium of cells was determined. The expression of markers of chondrocyte proliferation and differentiation, the Indian hedgehog (Ihh), and parathyroid hormone-related protein (PTHrP) pathway were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting. RESULTS The expression of SLC20A2 in MUT group was similar to WT group. The Pi concentration in the medium of cells in MUT group was significantly higher than WT group, which meant the SLC20A2 mutation inhibited Pi uptake in ATDC5 chondrocytes. The proliferation rate of ATDC5 chondrocytes in MUT group was greater than WT group. The expression of aggrecan (Acan), α-1 chain of type II collagen (COL2A1), and SRY-box transcription factor 9 (SOX9) were higher in MUT group than WT group. However, the expression of Runt-related transcription factor 2 (Runx2), α-1 chain of type X collagen (COL10A1), and matrix metallopeptidase 13 (MMP13) was significantly decreased in the MUT group. Similar results were obtained by Alcian blue and Alizarin red staining. The expression of Ihh and PTHrP in MUT group was higher than WT group. An inhibitor (cyclopamine) of Ihh/PTHrP signalling pathway inhibited the proliferation and restored the differentiation of chondrocytes in MUT group. CONCLUSION A mutation in SLC20A2 (c.C1948T) decreases Pi uptake in ATDC5 chondrocytes. SLC20A2 mutation promotes chondrocyte proliferation while inhibiting chondrocyte differentiation. The Ihh/PTHrP signalling pathway may play an important role in this process. Cite this article: Bone Joint Res 2020;9(11):751-760.
Collapse
Affiliation(s)
- YiQiang Li
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - XueMei Lin
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - MingWei Zhu
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - FuXing Xun
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - JingChun Li
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Zhe Yuan
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - YanHan Liu
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - HongWen Xu
- Department of Pediatric Orthopaedics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| |
Collapse
|
15
|
Li Y, Lin X, Zhu M, Li J, Yuan Z, Xu H. Whole‑exome sequencing identifies a novel mutation of SLC20A2 (c.C1849T) as a possible cause of hereditary multiple exostoses in a Chinese family. Mol Med Rep 2020; 22:2469-2477. [PMID: 32705272 PMCID: PMC7411400 DOI: 10.3892/mmr.2020.11298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/04/2020] [Indexed: 12/11/2022] Open
Abstract
Although the main causative genes for hereditary multiple exostoses (HME) are exostosin (EXT)‑1 and EXT‑2, there are numerous patients with HME without EXT‑1 and EXT‑2 mutations. The present study aimed to identify novel candidate genes for the development of HME in patients without EXT‑1 and EXT‑2 mutations. Whole‑exome sequencing was performed in a Chinese family with HME and without EXT‑1 and EXT‑2 mutations, followed by a combined bioinformatics pipeline including annotation and filtering processes to identify candidate variants. Candidate variants were then validated using Sanger sequencing. A total of 1,830 original variants were revealed to be heterozygous mutations in three patients with HME which were not present in healthy controls. Two mutations [c.C1849T in solute carrier family 20 member 2 (SLC20A2) and c.G506A in leucine zipper and EF‑hand containing transmembrane protein 1 (LETM1)] were identified as possible causative variants for HME through a bioinformatics filtering procedure and harmful prediction. Sanger sequencing results confirmed these two mutations in all patients with HME. A mutation in SLC20A2 (c.C1849T) led to a change in an amino acid (p.R617C), which may be involved in the development of HME by inducing metabolic disorders of phosphate and abnormal proliferation and differentiation in chondrocytes. In conclusion, the present study revealed two mutations [SLC20A2 (c.C1849T) and LETM1 (c.G506A) in a Chinese family with HME. The mutation in SLC20A2 (c.C1849T)] was more likely to be involved in the development of HME.
Collapse
Affiliation(s)
- Yiqiang Li
- Department of Pediatric Orthopedics, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, P.R. China
| | - Xuemei Lin
- Department of Pediatric Orthopedics, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, P.R. China
| | - Mingwei Zhu
- Department of Pediatric Orthopedics, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, P.R. China
| | - Jingchun Li
- Department of Pediatric Orthopedics, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, P.R. China
| | - Zhe Yuan
- Department of Pediatric Orthopedics, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, P.R. China
| | - Hongwen Xu
- Department of Pediatric Orthopedics, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, P.R. China
| |
Collapse
|
16
|
Fusco C, Nardella G, Fischetto R, Copetti M, Petracca A, Annunziata F, Augello B, D'Asdia MC, Petrucci S, Mattina T, Rella A, Cassina M, Bengala M, Biagini T, Causio FA, Caldarini C, Brancati F, De Luca A, Guarnieri V, Micale L, D'Agruma L, Castori M. Mutational spectrum and clinical signatures in 114 families with hereditary multiple osteochondromas: insights into molecular properties of selected exostosin variants. Hum Mol Genet 2020; 28:2133-2142. [PMID: 30806661 DOI: 10.1093/hmg/ddz046] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/22/2019] [Accepted: 02/22/2019] [Indexed: 01/05/2023] Open
Abstract
Hereditary multiple osteochondromas (HMO) is a rare autosomal dominant skeletal disorder, caused by heterozygous variants in either EXT1 or EXT2, which encode proteins involved in the biogenesis of heparan sulphate. Pathogenesis and genotype-phenotype correlations remain poorly understood. We studied 114 HMO families (158 affected individuals) with causative EXT1 or EXT2 variants identified by Sanger sequencing, or multiplex ligation-dependent probe amplification and qPCR. Eighty-seven disease-causative variants (55 novel and 32 known) were identified including frameshift (42%), nonsense (32%), missense (11%), splicing (10%) variants and genomic rearrangements (5%). Informative clinical features were available for 42 EXT1 and 27 EXT2 subjects. Osteochondromas were more frequent in EXT1 as compared to EXT2 patients. Anatomical distribution of lesions showed significant differences based on causative gene. Microscopy analysis for selected EXT1 and EXT2 variants verified that EXT1 and EXT2 mutants failed to co-localize each other and loss Golgi localization by surrounding the nucleus and/or assuming a diffuse intracellular distribution. In a cell viability study, cells expressing EXT1 and EXT2 mutants proliferated more slowly than cells expressing wild-type proteins. This confirms the physiological relevance of EXT1 and EXT2 Golgi co-localization and the key role of these proteins in the cell cycle. Taken together, our data expand genotype-phenotype correlations, offer further insights in the pathogenesis of HMO and open the path to future therapies.
Collapse
Affiliation(s)
- Carmela Fusco
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Grazia Nardella
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.,Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Rita Fischetto
- Unit of Metabolic Diseases and Medical Genetics, University Hospital, P.O. Giovanni XXIII Hospital, Bari, Italy
| | - Massimiliano Copetti
- Unit of Biostatistics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Antonio Petracca
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Francesca Annunziata
- Unit of Molecular Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Bartolomeo Augello
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Maria Cecilia D'Asdia
- Unit of Molecular Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Simona Petrucci
- Unit of Molecular Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.,Department of Clinical and Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Teresa Mattina
- Unit of Medical Genetics, University of Catania, Catania, Italy
| | - Annalisa Rella
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Matteo Cassina
- Unit of Clinical Genetics, Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Mario Bengala
- Dipartimento di Oncoematologia, U.O.C Laboratorio di Genetica Medica, Fondazione Policlinico di Tor Vergata, Rome, Italy
| | - Tommaso Biagini
- Unit of Bioinformatics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Francesco Andrea Causio
- Unit of Metabolic Diseases and Medical Genetics, University Hospital, P.O. Giovanni XXIII Hospital, Bari, Italy
| | - Camilla Caldarini
- Division of Orthopedics and Traumatology, Azienda Socio Sanitaria Territoriale Gaetano Pini, Milan, Italy
| | - Francesco Brancati
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.,Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata (IDI) IRCCS, Rome, Italy
| | - Alessandro De Luca
- Unit of Molecular Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Vito Guarnieri
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Lucia Micale
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Leonardo D'Agruma
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Marco Castori
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| |
Collapse
|
17
|
Oliver GR, Blackburn PR, Ellingson MS, Conboy E, Pinto E Vairo F, Webley M, Thorland E, Ferber M, Van Hul E, van der Werf IM, Wuyts W, Babovic-Vuksanovic D, Klee EW. RNA-Seq detects a SAMD12-EXT1 fusion transcript and leads to the discovery of an EXT1 deletion in a child with multiple osteochondromas. Mol Genet Genomic Med 2019; 7:e00560. [PMID: 30632316 PMCID: PMC6418362 DOI: 10.1002/mgg3.560] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/29/2018] [Accepted: 12/13/2018] [Indexed: 12/24/2022] Open
Abstract
Background We describe a patient presenting with pachygyria, epilepsy, developmental delay, short stature, failure to thrive, facial dysmorphisms, and multiple osteochondromas. Methods The patient underwent extensive genetic testing and analysis in an attempt to diagnose the cause of his condition. Clinical testing included metaphase karyotyping, array comparative genomic hybridization, direct sequencing and multiplex ligation‐dependent probe amplification and trio‐based exome sequencing. Subsequently, research‐based whole transcriptome sequencing was conducted to determine whether it might shed light on the undiagnosed phenotype. Results Clinical exome sequencing of patient and parent samples revealed a maternally inherited splice‐site variant in the doublecortin (DCX) gene that was classified as likely pathogenic and diagnostic of the patient's neurological phenotype. Clinical array comparative genome hybridization analysis revealed a 16p13.3 deletion that could not be linked to the patient phenotype based on affected genes. Further clinical testing to determine the cause of the patient's multiple osteochondromas was unrevealing despite extensive profiling of the most likely causative genes, EXT1 and EXT2, including mutation screening by direct sequence analysis and multiplex ligation‐dependent probe amplification. Whole transcriptome sequencing identified a SAMD12‐EXT1 fusion transcript that could have resulted from a chromosomal deletion, leading to the loss of EXT1 function. Re‐review of the clinical array comparative genomic hybridization results indicated a possible unreported mosaic deletion affecting the SAMD12 and EXT1 genes that corresponded precisely to the introns predicted to be affected by a fusion‐causing deletion. The existence of the mosaic deletion was subsequently confirmed clinically by an increased density copy number array and orthogonal methodologies Conclusions While mosaic mutations and deletions of EXT1 and EXT2 have been reported in the context of multiple osteochondromas, to our knowledge, this is the first time that transcriptomics technologies have been used to diagnose a patient via fusion transcript analysis in the congenital disease setting.
Collapse
Affiliation(s)
- Gavin R Oliver
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.,Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota
| | - Patrick R Blackburn
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Marissa S Ellingson
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Erin Conboy
- Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| | - Filippo Pinto E Vairo
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.,Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota
| | - Matthew Webley
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Erik Thorland
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Matthew Ferber
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Els Van Hul
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Ilse M van der Werf
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Wim Wuyts
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Dusica Babovic-Vuksanovic
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.,Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| | - Eric W Klee
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.,Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.,Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|