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Novel Ameloblastin Variants, Contrasting Amelogenesis Imperfecta Phenotypes
U Hany1, C M Watson1,2, L Liu1,3
1Leeds Institute of Medical Research, University of Leeds, St. James's University Hospital, Leeds, UK.
Journal of Dental Research
|December 7, 2023
Summary
New research identifies five novel pathogenic Ameloblastin (AMBN) variants in individuals with Amelogenesis Imperfecta (AI). These findings reveal complex inheritance patterns and diverse enamel phenotypes associated with AMBN gene mutations.
Area of Science:
- Genetics and Genomics
- Dental and Oral Health
- Biochemistry
Background:
- Amelogenesis imperfecta (AI) is a rare inherited disorder affecting enamel formation.
- Ameloblastin (AMBN), a key enamel matrix protein, is crucial for amelogenesis.
- Previously, pathogenic AMBN variants were primarily linked to recessive hypoplastic AI, with limited understanding of dominant inheritance and varied phenotypes.
Purpose of the Study:
- To characterize the full spectrum of human AI phenotypes associated with pathogenic AMBN variants.
- To investigate the inheritance patterns (dominant and recessive) of AMBN-related AI.
- To identify and analyze novel AMBN variants contributing to AI.
Main Methods:
- Clinical phenotyping of 11 individuals across 5 families with AI.
- Genetic analysis including sequencing of the AMBN locus.
- Genotyping and haplotype analysis to determine variant origins and inheritance.
Main Results:
- Identified 5 new pathogenic AMBN variants in 11 individuals with AI, categorized into three phenotypic groups.
- Observed both biallelic (recessive) and monoallelic (dominant) inheritance patterns for AMBN variants.
- Documented diverse AI phenotypes including yellow hypoplastic AI, hypomaturation AI with pitting, and white hypoplastic AI.
Conclusions:
- Pathogenic AMBN variants are associated with a broader range of AI phenotypes and inheritance patterns than previously recognized.
- The study supports both dominant and recessive modes of inheritance for AMBN-related AI.
- Findings underscore the complex role of AMBN in enamel formation and human AI.
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