WNT10A variants: following the pattern of inheritance in tooth agenesis and self-reported family history of cancer

Main genetic entities associated with tooth agenesis

BACKGROUND

Tooth agenesis refers to the absence of one or more of the deciduous or permanent teeth. Tooth agenesis results from a series of disrupted reciprocal ectodermal mesenchymal interactions taking place during the early stages of tooth development.

METHODS

A narrative literature review was performed to describe the main genetic syndromes associated with tooth agenesis.

RESULTS AND CONCLUSIONS

The etiology of congenital tooth agenesis is multifactorial and include genetic, epigenetic, and environmental influences. Syndromes associated with chromosomal alterations, ectodermal dysplasia, Axenfeld-Rieger syndrome, oral-facial cleft syndromes, and syndromes with cancer predisposition are among the main entities presenting with tooth agenesis.

CLINICAL RELEVANCE

Tooth agenesis disorders can affect the masticatory function and cause disfigurement leading to physiological and psychological complications. Early recognition of these entities is crucial to guide the management of the patient and to provide families with the appropriate genetic counseling.

Compound heterozygous WNT10A missense variations exacerbated the tooth agenesis caused by hypohidrotic ectodermal dysplasia

BACKGROUND

The aim of this study was to analyse the differences in the phenotypes of missing teeth between a pair of brothers with hypohidrotic ectodermal dysplasia (HED) and to investigate the underlying mechanism by comparing the mutated gene loci between the brothers with whole-exome sequencing.

METHODS

The clinical data of the patients and their mother were collected, and genomic DNA was extracted from peripheral blood samples. By Whole-exome sequencing filtered for a minor allele frequency (MAF) ≤0.05 non-synonymous single-nucleotide variations and insertions/deletions variations in genes previously associated with tooth agenesis, and variations considered as potentially pathogenic were assessed by SIFT, Polyphen-2, CADD and ACMG. Sanger sequencing was performed to detect gene variations. The secondary and tertiary structures of the mutated proteins were predicted by PsiPred 4.0 and AlphaFold 2.

RESULTS

Both brothers were clinically diagnosed with HED, but the younger brother had more teeth than the elder brother. An EDA variation (c.878 T > G) was identified in both brothers. Additionally, compound heterozygous variations of WNT10A (c.511C > T and c.637G > A) were identified in the elder brother. Digenic variations in EDA (c.878 T > G) and WNT10A (c.511C > T and c.637G > A) in the same patient have not been reported previously. The secondary structure of the variant WNT10A protein showed changes in the number and position of α-helices and β-folds compared to the wild-type protein. The tertiary structure of the WNT10A variant and molecular simulation docking showed that the site and direction where WNT10A binds to FZD5 was changed.

CONCLUSIONS

Compound heterozygous WNT10A missense variations may exacerbate the number of missing teeth in HED caused by EDA variation.