LRP6 β-Propeller Destabilization: Novel Variant, Phenotype and Diagnostic Implications in Tooth Agenesis

Abstract

Background and Objectives

Oligodontia, the congenital absence of multiple permanent teeth, is frequently linked to LRP6 variants. However, the genotype–phenotype correlations remain unclear and non-European cohorts are underrepresented. The objectives of this study were to: (1) characterize the molecular and clinical features of LRP6 variants identified in unrelated Thai individuals with tooth agenesis; (2) conduct a scoping review of previously published cases; and (3) refine the understanding of LRP6 genotype–phenotype correlations.

Materials and Methods

A detailed case series analysis of Thai families with congenital tooth agenesis (through exome sequencing and 3D protein modelling) was conducted, and functional validation was performed using computational structural prediction. A reviewed published cases of LRP6 variants was performed following a PRISMA-ScR-guided scoping review (2005-2025).

Results

p.Asp411Tyr, a novel heterozygous de novo missense change, destabilised the β-propeller domain. While Thai probands expanded the phenotype and genotype spectrum of LRP6-associated tooth agenesis, a review of 20 studies showed clustering of variants in β-propeller domains (62%), usually autosomal dominant (78%) but with variable penetrance. The phenotypes ranged from isolated oligodontia to syndromic forms. Thai probands displayed rare ectodermal-associated features (preauricular pits, dry skin) expanding the spectrum.

Conclusion

LRP6 is a mutational hotspot in tooth development, with variable phenotypical expressivity and penetrance.