Dataset Information

The phenotypic characteristics of patients with athelia and tooth agenesis

ABSTRACT:

Background

Although athelia, which is a congenital aplastic deformity of the nipple, is seldom reported in tooth agenesis patients, we observed athelia in 2 hypodontia patients. This study aimed to summarize the phenotypic characteristics of patients with athelia and tooth agenesis.

Methods

A database search was conducted for publications reporting on patients with athelia and tooth agenesis, and the phenotypes of such patients were recorded. Athelia-related syndromes were identified in the Online Mendelian Inheritance in Man (OMIM) database. The common symptoms and the causative genes were documented. Potential interactions between athelia-related genes and tooth agenesis-related genes were analyzed in the Database for Annotation, Visualization, and Integrated Discovery (DAVID) Bioinformatics Resources and the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database.

Results

We summarized the phenotypic characteristics of 8 previously reported patients. Deformities in hair, skin, and sweat glands were common in these patients. There were 23 nipple deformity-related syndromes reported. The most common symptoms included abnormalities of the head and neck, cardiovascular, genitourinary, and skeletal systems, and the skin, nails, and hair. Hypodontia was noted in association with 10 syndromes. A total of 16 genes were related to them, including TP63, KCTD1, and IKBKG. The interaction found in the study suggests that nipple deformity-related genes potentially interact with tooth agenesis-related genes.

Conclusions

These results indicated that athelia might be related to hypodontia. Additional molecular genetics research is needed to fully elucidate the underlying relationship between athelia and tooth agenesis.

SUBMITTER: Chen X

PROVIDER: S-EPMC8576720 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Tooth agenesis is one of the most common orodental anomalies that demonstrate phenotypic and genotypic heterogeneity with a prevalence of 2.5%-7%. Mutations in WNT10A have been proposed to be the most common cause of nonsyndromic tooth agenesis (NSTA). The aim of this study was to characterize the dental features and genetic variants of NSTA in a Thai population. We recruited 13 unrelated patients with NSTA who attended the Faculty of Dentistry, Chulalongkorn University, Thailand, from 2017 to 2019. All 13 underwent whole exome sequencing that identified likely pathogenic genetic variants, all in WNT10A, in five patients. All five patients had second premolar agenesis, while three also had absent or peg-shaped upper lateral incisors. Patient 1 possessed a novel heterozygous duplication, c.916_918dupAAC (p.Asn306dup) in WNT10A. Patients 2 and 3 harbored a heterozygous and homozygous c.637G > A (p.Gly213Ser) in WNT10A, respectively. Patients 4 possessed a heterozygous c.511C > T (p.Arg171Cys) in WNT10A. Patient 5 harbored a homozygous c.511C > T (p.Arg171Cys) in WNT10A and a novel heterozygous c.413A > T (p.Asn138Ile) in EDARADD, suggesting digenic inheritance. We recruited another 18 family members of these five patients. Out of 23 participants, homozygous WNT10A variants were identified in 2 patients and heterozygous variants in 17 individuals. Both homozygous patients had NSTA. Eight out of 17 heterozygous individuals (8/17) had NSTA or a peg-shaped lateral incisor, indicating a 47% penetrance of the heterozygous variants or 53% (10/19) penetrance of either homozygous or heterozygous variants in WNT10A. The frequencies of the c.511C > T in our in-house 1,876 Thai exome database, Asian populations, and non-Asian populations were 0.016, 0.005-0.033, and 0.001, respectively; while those of the c.637G > A were 0.016, 0.004-0.029, and 0.000, respectively. In conclusion, our study reports two novel variants with one each in WNT10A and EDARADD, expanding the genotypic spectra of NSTA. Second premolar agenesis is a common phenotype in affected individuals with variants in WNT10A; however, its penetrance is incomplete. Lastly, the different frequencies of WNT10A variants, c.511C > T and c.637G > A, in diverse populations might contribute to the prevalence range of NSTA between continents.

Project description:Since MSX1 and PAX9 are linked to the pathogenesis of nonsyndromic tooth agenesis, we performed detailed mutational analysis of these two genes sampled from Japanese patients. We identified two novel MSX1 variants with an amino acid substitution within the homeodomain; Thr174Ile (T174I) from a sporadic hypodontia case and Leu205Arg (L205R) from a familial oligodontia case. Both the Thr174 and Leu205 residues in the MSX1 homeodomain are highly conserved among different species. To define possible roles of mutations at these amino acids in the pathogenesis of nonsyndromic tooth agenesis, we performed several functional analyses. It has been demonstrated that MSX1 plays a pivotal role in hard tissue development as a suppressor for mesenchymal cell differentiation. To evaluate the suppression activity of the variants in mesenchymal cells, we used the myoD-promoter, which is one of convenient reporter assay system for MSX1. Although the gene products of these MSX1 variants are stable and capable of normal nuclear localization, they do not suppress myoD-promoter activity in differentiated C2C12 cells. To clarify the molecular mechanisms underlying our results, we performed further analyses including electrophoretic mobility shift assays, and co-immunoprecipitation assays to survey the molecular interactions between the mutant MSX1 proteins and the oligonucleotide DNA with MSX1 consensus binding motif or EZH2 methyltransferase. Since EZH2 is reported to interact with MSX1 and regulate MSX1 mediated gene suppression, we hypothesized that the T174I and L205R substitutions would impair this interaction. We conclude from the results of our experiments that the DNA binding ability of MSX1 is abolished by these two amino acid substitutions. This illustrates a causative role of the T174I and L205R MSX1 homeodomain mutations in tooth agenesis, and suggests that they may influence cell proliferation and differentiation resulting in lesser tooth germ formation in vivo.