Related Experiment Videos
Dentin phosphoprotein compound mutation in dentin sialophosphoprotein causes dentinogenesis imperfecta type III
Juan Dong1, TingTing Gu, Leticia Jeffords
1Department of Pediatric Dentistry, Dental School, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA.
American Journal of Medical Genetics. Part A
|February 4, 2005
Summary
A rare mutation in the dentin sialophosphoprotein (DSPP) gene causes dentinogenesis imperfecta type III (DGI-III), leading to discolored teeth and severe attrition. This finding links DSPP gene mutations to a spectrum of dentin disorders.
Area of Science:
- Genetics
- Dentistry
- Molecular Biology
Background:
- Dentinogenesis imperfecta type III (DGI-III) is a rare genetic disorder affecting tooth development.
- The dentin sialophosphoprotein (DSPP) gene encodes key proteins (dentin sialoprotein and dentin phosphoprotein) crucial for dentin matrix formation.
- Previous studies have linked DSPP gene mutations to other forms of dentinogenesis imperfecta and dentin dysplasia.
Purpose of the Study:
- To identify the genetic cause of DGI-III in a consanguineous family.
- To characterize the specific mutation within the DSPP gene and its effect on protein structure.
- To investigate the allelic relationship between DGI-III and other DSPP-related dentin disorders.
Main Methods:
- Genetic analysis of the DSPP gene in affected family members.
- Sequencing of DSPP gene exons to identify mutations.
- Clinical examination of affected individuals to document dental and auditory phenotypes.
Main Results:
- A novel compound mutation (36 bp deletion and 18 bp insertion) was identified in exon 5 of the DSPP gene in affected individuals.
- This mutation results in an in-frame truncation of the dentin phosphoprotein (DPP) component of DSPP, altering a critical repeat region.
- Affected family members exhibited characteristic DGI-III clinical features: amber opalescent teeth and severe attrition.
Conclusions:
- This study reports the first DSPP gene mutation associated with DGI-III, identifying a specific genetic defect.
- The findings suggest that DGI-III is allelic to certain forms of DGI-II and dentin dysplasia type II, indicating a shared genetic pathway.
- DSPP mutations represent a significant cause of inherited dentin disorders, highlighting the gene's critical role in tooth mineralization.