A novel missense mutation of LRP6 identified by whole-exome sequencing in a Chinese family with non-syndromic tooth agenesis

Objective: The aim of this study was to explore the genetic basis of non-syndromic tooth agenesis (TA) in a Chinese family of five individuals using whole-exome sequencing (WES) analysis.

Settings and sample population: Five participants/Family-based study of a non-syndromic TA proband.

Methods: The proband, proband's mother and grandmother displayed congenital tooth deficiency. Genomic DNA was extracted from the peripheral blood or saliva samples of the proband, her parents and her grandmother, and WES was utilized to identify the causal genetic mutation. The identified mutation was further verified by Sanger sequencing and analysed using bioinformatics tools.

Results: A novel missense mutation, c.G711T (p.L237F), was identified in the low-density lipoprotein receptor-related protein 6 (LRP6) gene in all affected individuals. Bioinformatics analysis predicted the mutation to be deleterious, with the mutant LRP6 protein displaying a tertiary structural change that might disturb the Wnt/β-catenin signalling pathway.

Conclusions: The identification of the mutation in the LRP6 gene and autosomal dominant inheritance with TA in the generations is consistent with the mutation being responsible for TA in the family, and furthers the association of LRP6 with nonsyndromic TA.