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Published on: July 3, 2020
Recessive oligodontia linked to a homozygous loss-of-function mutation in the SMOC2 gene
1Centre for Oral Growth & Development, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK.
Objective:
Recently, several genes have been reported with mutations or variants that underlie a number of syndromic and non-syndromic forms of oligodontia including MSX1, PAX9, AXIN2, EDA and WNT10A. This study aimed to identify the causal mutations in a consanguineous Pakistan family with oligodontia and microdontia.
Design:
Exome sequencing was performed in two of affected members of the Pakistan family.
Results:
The exome sequencing data revealed that the affected individuals were homozygous with a novel mutation in exon 8 of the SMOC2 gene, c.681T>A (p.C227X).
Conclusions:
This is the second report describing SMOC2 mutations with oligodontia and microdontia underlining the key role for this signalling molecule in tooth development.
Insights
Researchers identified a novel SMOC2 gene mutation in a Pakistani family with oligodontia and microdontia. This finding highlights SMOC2
Area of Science:
- Genetics
- Developmental Biology
- Oral Health
Background:
- Oligodontia (congenital absence of multiple teeth) and microdontia (small teeth) can be syndromic or non-syndromic.
- Genetic factors, including mutations in genes like MSX1, PAX9, AXIN2, EDA, and WNT10A, are known causes of these conditions.
- Identifying novel genetic underpinnings is crucial for understanding tooth development and diagnosing affected individuals.
Purpose of the Study:
- To identify the specific genetic cause of oligodontia and microdontia in a consanguineous Pakistani family.
- To investigate the role of novel gene mutations in the etiology of tooth agenesis.
Main Methods:
- Whole exome sequencing was conducted on two affected members of the Pakistani family.
- Bioinformatic analysis was used to identify genetic variants.
- Segregation analysis was performed to confirm the causative mutation.
Main Results:
- A novel homozygous mutation, c.681T>A (p.C227X), was identified in exon 8 of the SMOC2 gene in affected individuals.
- This mutation leads to a premature stop codon, likely resulting in a non-functional protein.
- The identified mutation was absent in unaffected family members, confirming its association with the phenotype.
Conclusions:
- This study reports the second instance of SMOC2 gene mutations associated with oligodontia and microdontia.
- The findings underscore the critical role of the SMOC2 gene and its encoded protein in mammalian tooth development.
- Further research into SMOC2 function can provide insights into developmental pathways and potential therapeutic targets.
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