PUBLICATION

A novel phex gene variant causes non-syndromic tooth agenesis

Authors
Pan, Y., Hua, B., Wang, H., Tan, S., Lu, T., Xiong, F., Ma, D.
ID
ZDB-PUB-250927-35
Date
2025
Source
BMC oral health   25: 14521452 (Journal)
Registered Authors
Keywords
Mutation, Non-syndromic tooth agenesis, PHEX
MeSH Terms
  • Pedigree
  • Zebrafish
  • PHEX Phosphate Regulating Neutral Endopeptidase*/genetics
  • Female
  • Phenotype
  • Dental Pulp/cytology
  • Anodontia*/genetics
  • Genetic Variation
  • Male
  • Humans
  • Exome Sequencing
  • Animals
PubMed
41013490 Full text @ BMC Oral Health
Abstract
For a long time, phosphate regulating endopeptidase X-linked (phex) gene variants have been considered the primary cause of hypophosphatemic rickets. Here, we recruited a pedigree with non-syndromic tooth agenesis (NSTA), where all patients exhibit solely the absence of mandibular central incisors, indicating a highly conserved clinical phenotype. This observation leads us to hypothesize a potential connection between phex variants and NSTA.
Whole-exome sequencing and genetic co-segregation analysis were employed to investigate the genetic basis of NSTA in this family. To further explore this hypothesis, we used phex knockdown zebrafish models and dental pulp stem cells (DPSCs) from the patient (DPSCs-MUT) and normal control (DPSCs-CON) to assess tooth development and cellular functions.
We identified a novel PHEX variant (NM_000444.5 c.1763 A > T, p.N588I) that co-segregated with the NSTA phenotype. The phex knockdown zebrafish displayed a tooth loss phenotype, which closely aligns with characteristics of NSTA. Additionally, DPSCs-MUT exhibited significantly reduced mineralization and proliferation capabilities compared to DPSCs-CON, along with increased enzymatic activity. These findings suggest that PHEX variants adversely affect DPSC function. Transcriptome sequencing analysis of the DPSCs revealed significant differences in gene expression between DPSCs-MUT and DPSCs-CON. Specifically, genes linked to the cGMP-PKG signaling pathway were abnormally expressed, implicating this pathway in the potential pathogenesis of NSTA due to PHEX variants.
Collectively, this study offers a foundation for further research on the relationship between PHEX variants and NSTA, which could enhance the diagnosis and treatment strategies for this condition in the future.
Our research not only advances the understanding of NSTA pathogenic mechanisms but also expands the phenotypic spectrum associated with PHEX variants, highlighting its role beyond phosphate homeostasis in the development of specific dental structures.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping