Mutations in LRP6 highlight the role of WNT signaling in oral exostoses and dental anomalies

Arch Oral Biol. 2022 Oct:142:105514. doi: 10.1016/j.archoralbio.2022.105514. Epub 2022 Jul 30.

Abstract

Objective: The objective of this study was to investigate molecular etiologies of oral exostoses and dental anomalies in 14 patients from eight families.

Methods: Oral and radiographic examinations were performed on every patient. Whole exome and Sanger sequencing were performed on DNA of the patients, the unaffected parents and unaffected siblings. LRP6 mutant proteins were modeled and analyzed.

Results: Five mutations in LRP6, including four missense (p.Glu72Lys, p.Lys82Asn, Tyr418His, and p.Ile773Val) and one nonsense mutation (p.Arg32Ter), were identified. These mutations have not been reported to be associated with dental anomalies or oral exostoses. Oral features included a variety of oral exostoses (7 of the 14 patients), root defects (6 of the 14 patients), and tooth agenesis (5 of the 14 patients). Less common dental anomalies included microdontia, tooth fusion, odontomas, and mesiodens. Analysis of the protein models of the five LRP6 mutations shed light on their likely impact on LRP6 protein structure and function.

Conclusion: Fourteen patients with five LRP6 mutations, including two recurrent mutations and three novel ones, are reported. Our study shows for the first time that mutations in LRP6 are associated with mesiodens, fusion of teeth, odontomas, microdontia, long roots, molars with unseparated roots, and taurodontism.

Keywords: Fusion of teeth; Mesiodens; Odontoma; Root anomalies; Torus mandibularis; Torus palatinus.

MeSH terms

  • Exostoses*
  • Humans
  • Low Density Lipoprotein Receptor-Related Protein-6 / genetics
  • Mutation
  • Odontoma*
  • Tooth Abnormalities* / genetics
  • Tooth, Supernumerary*
  • Wnt Signaling Pathway

Substances

  • LRP6 protein, human
  • Low Density Lipoprotein Receptor-Related Protein-6