Martínez-Gil, NúriaRoca Ayats, NeusAtalay, NurgülPineda-Moncusí, MartaGarcia Giralt, NatàliaVan Hul, WimBoudin, EvelineOvejero Crespo, DianaMellibovsky, LeonardoNogués Solan, Francesc XavierDiez-Perez, AdolfoGrinberg, DanielBalcells, Susana2021-07-262021-07-262020Martínez-Gil N, Roca-Ayats N, Atalay N, Pineda-Moncusí M, Garcia-Giralt N, Van Hul W, et al. Functional assessment of coding and regulatory variants from the DKK1 locus. JBMR Plus. 2020 Nov 2; 4(12): e10423. DOI: 10.1002/jbm4.104232473-4039http://hdl.handle.net/10230/48295The DKK1 gene encodes an extracellular inhibitor of the Wnt pathway with an important role in bone tissue development, bone homeostasis, and different critical aspects of bone biology. Several BMD genome-wide association studies (GWASs) have consistently found association with SNPs in the DKK1 genomic region. For these reasons, it is important to assess the functionality of coding and regulatory variants in the gene. Here, we have studied the functionality of putative regulatory variants, previously found associated with BMD in different studies by others and ourselves, and also six missense variants present in the general population. Using a Wnt-pathway-specific luciferase reporter assay, we have determined that the variants p.Ala41Thr, p.Tyr74Phe, p.Arg120Leu, and p.Ser157Ile display a reduced DKK1 inhibitory capacity as compared with WT. This result agrees with the high-bone-mass (HBM) phenotype of two women from our cohort who carried mutations p.Tyr74Phe or p.Arg120Leu. On the other hand, by means of a circularized chromosome conformation capture- (4C-) sequencing experiment, we have detected that the region containing 24 BMD-GWA variants, located 350-kb downstream of DKK1, interacts both with DKK1 and the LNCAROD (LncRNA-activating regulator of DKK1, AKA LINC0148) in osteoblastic cells. In conclusion, we have shown that some rare coding variants are partial loss-of-function mutations that may lead to a HBM phenotype, whereas the common SNPs associated with BMD in GWASs belong to a putative long-range regulatory region, through a yet unknown mechanism involving LNCAROD. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.application/pdfengCopyright © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Copyright © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1002/jbm4.10423Bone diseases and disordesCells of bone osteoblastsGenetic researchMolecular pathways remodelingOsteoporosisWNT/β‐CATENIN/LRPsinfo:eu-repo/semantics/openAccess