TY - JOUR
T1 - Mutations in Fibronectin Cause a Subtype of Spondylometaphyseal Dysplasia with “Corner Fractures”
AU - Baylor-Hopkins Center for Mendelian Genomics
AU - Lee, Chae Syng
AU - Fu, He
AU - Baratang, Nissan
AU - Rousseau, Justine
AU - Kumra, Heena
AU - Sutton, V. Reid
AU - Niceta, Marcello
AU - Ciolfi, Andrea
AU - Yamamoto, Guilherme
AU - Bertola, Débora
AU - Marcelis, Carlo L.
AU - Lugtenberg, Dorien
AU - Bartuli, Andrea
AU - Kim, Choel
AU - Hoover-Fong, Julie
AU - Sobreira, Nara
AU - Pauli, Richard
AU - Bacino, Carlos
AU - Krakow, Deborah
AU - Parboosingh, Jillian
AU - Yap, Patrick
AU - Kariminejad, Ariana
AU - McDonald, Marie T.
AU - Aracena, Mariana I.
AU - Lausch, Ekkehart
AU - Unger, Sheila
AU - Superti-Furga, Andrea
AU - Lu, James T.
AU - Cohn, Dan H.
AU - Tartaglia, Marco
AU - Lee, Brendan H.
AU - Reinhardt, Dieter P.
AU - Campeau, Philippe M.
N1 - Funding Information:
This project was supported in part by operating grants from the Canadian Institutes for Health Research (clinician-scientist award RN315908 to P.M.C.; MOP-137091 to D.P.R.), the Fonds de Recherche du Québec - Santé clinical research scholar award 30647 to P.M.C., the Quebec Network for Oral and Bone Health Research (RSBO Emerging Collaborating Project 2014-2015 to P.M.C. and D.P.R.), the NIH (UM1 HG006542 to the Baylor Hopkins Center for Mendelian Genomics), the Heart and Stroke Foundation of Canada (G-16-00014634 to D.P.R.), the Italian Ministry of Health (Ricerca Corrente 2016 to M.T. and M.N.), and Fondazione Bambino Gesù (Vite Coraggiose grant to M.T.). This work was also supported by NIH P01 HD070394, by HD024064 from the Eunice Kennedy Shriver National Institute of Child Health & Human Development granted to the Baylor College of Medicine (BCM) Intellectual and Developmental Disabilities Research Center (for processing samples obtained and managing clinical protocols), by the BCM Advanced Technology Cores through funding from the NIH (AI036211, CA125123, and RR024574), by the Rolanette and Berdon Lawrence Bone Disease Program of Texas, and by the BCM Center for Skeletal Medicine and Biology (to B.H.L). Analysis of individual 5 was supported by the São Paulo Research Foundation (FAPESP 2015/21783-9; Centros de Pesquisa, Inovação, e Difusão [CEPID] 2013/08028-1) and National Council for Scientific and Technological Development (CNPq 302605/2013-4 and 304130/2016-8 to D. B). E.L. is supported by grants from the German Research Foundation (CRC 1140), the German Ministry for Education and Research (MaTrOC), and the European Union (SYBIL grant agreement no. 602300; RARENET). We thank Dr. Deane Mosher and Dr. Douglas Annis for providing the FN1 pAcGP67A plasmid. We thank Dr. Reggie Hamdy for referring individual 7 to Dr. Campeau and Dr. Amélie Damphousse for the interpretation of the radiographs.
Publisher Copyright:
© 2017 American Society of Human Genetics
PY - 2017/11/2
Y1 - 2017/11/2
N2 - Fibronectin is a master organizer of extracellular matrices (ECMs) and promotes the assembly of collagens, fibrillin-1, and other proteins. It is also known to play roles in skeletal tissues through its secretion by osteoblasts, chondrocytes, and mesenchymal cells. Spondylometaphyseal dysplasias (SMDs) comprise a diverse group of skeletal dysplasias and often manifest as short stature, growth-plate irregularities, and vertebral anomalies, such as scoliosis. By comparing the exomes of individuals with SMD with the radiographic appearance of “corner fractures” at metaphyses, we identified three individuals with fibronectin (FN1) variants affecting highly conserved residues. Furthermore, using matching tools and the SkelDys emailing list, we identified other individuals with de novo FN1 variants and a similar phenotype. The severe scoliosis in most individuals and rare developmental coxa vara distinguish individuals with FN1 mutations from those with classical Sutcliffe-type SMD. To study functional consequences of these FN1 mutations on the protein level, we introduced three disease-associated missense variants (p.Cys87Phe [c.260G>T], p.Tyr240Asp [c.718T>G], and p.Cys260Gly [c.778T>G]) into a recombinant secreted N-terminal 70 kDa fragment (rF70K) and the full-length fibronectin (rFN). The wild-type rF70K and rFN were secreted into the culture medium, whereas all mutant proteins were either not secreted or secreted at significantly lower amounts. Immunofluorescence analysis demonstrated increased intracellular retention of the mutant proteins. In summary, FN1 mutations that cause defective fibronectin secretion are found in SMD, and we thus provide additional evidence for a critical function of fibronectin in cartilage and bone.
AB - Fibronectin is a master organizer of extracellular matrices (ECMs) and promotes the assembly of collagens, fibrillin-1, and other proteins. It is also known to play roles in skeletal tissues through its secretion by osteoblasts, chondrocytes, and mesenchymal cells. Spondylometaphyseal dysplasias (SMDs) comprise a diverse group of skeletal dysplasias and often manifest as short stature, growth-plate irregularities, and vertebral anomalies, such as scoliosis. By comparing the exomes of individuals with SMD with the radiographic appearance of “corner fractures” at metaphyses, we identified three individuals with fibronectin (FN1) variants affecting highly conserved residues. Furthermore, using matching tools and the SkelDys emailing list, we identified other individuals with de novo FN1 variants and a similar phenotype. The severe scoliosis in most individuals and rare developmental coxa vara distinguish individuals with FN1 mutations from those with classical Sutcliffe-type SMD. To study functional consequences of these FN1 mutations on the protein level, we introduced three disease-associated missense variants (p.Cys87Phe [c.260G>T], p.Tyr240Asp [c.718T>G], and p.Cys260Gly [c.778T>G]) into a recombinant secreted N-terminal 70 kDa fragment (rF70K) and the full-length fibronectin (rFN). The wild-type rF70K and rFN were secreted into the culture medium, whereas all mutant proteins were either not secreted or secreted at significantly lower amounts. Immunofluorescence analysis demonstrated increased intracellular retention of the mutant proteins. In summary, FN1 mutations that cause defective fibronectin secretion are found in SMD, and we thus provide additional evidence for a critical function of fibronectin in cartilage and bone.
KW - FN1
KW - cartilage
KW - corner fractures
KW - extracellular matrix
KW - fibronectin
KW - metaphyses
KW - protein secretion
KW - scoliosis
KW - skeletal dysplasia
KW - spondylometaphyseal
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U2 - 10.1016/j.ajhg.2017.09.019
DO - 10.1016/j.ajhg.2017.09.019
M3 - Article
C2 - 29100092
AN - SCOPUS:85033555365
VL - 101
SP - 815
EP - 823
JO - American Journal of Human Genetics
JF - American Journal of Human Genetics
SN - 0002-9297
IS - 5
ER -