title: Characterisation of molecular defects in X-linked amelogenesis imperfecta (AIH1).
abstract: Amelogenins are an heterogenous family of proteins produced by ameloblasts of the enamel organ during tooth development. Disturbances of enamel formation occur in amelogenesis imperfecta, a clinically heterogenous group of inherited disorders characterised by defective enamel biomineralisation. An amelogenin gene, AMGX, has been mapped to the short of the X chromosome (Xp22.1-p22.3) and has been implicated in the molecular pathology of X-linked amelogenesis imperfecta (AIH1). We have identified three families exhibiting AIH1 and screened the AMGX gene for mutations using single-strand conformational polymorphism analysis and DNA sequencing. Three novel mutations were identified: a C-T substitution in exon 5, and a G-T substitution and single cytosine deletion in exon 6, confirming the existence of extensive allelic heterogeneity in this condition. The identification of family-specific mutations will enable early identification of affected individuals and correlation of clinical phenotype with genotype will facilitate an objective system of disease classification.
authors.affiliation: Division of Oral Surgery, Leeds Dental Institute, United Kingdom.
authors.forename: N J
authors.initials: NJ
authors.lastname: Lench
authors.forename: G B
authors.initials: GB
authors.lastname: Winter
mesh_terms: D000567:Amelogenesis Imperfecta / Q000235:genetics*; D053523:Amelogenin; D001483:Base Sequence; D003746:Dental Enamel Proteins / Q000235:genetics*; D005091:Exons; D005260:Female; D018740:Genetic Heterogeneity; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D017422:Sequence Analysis, DNA; D014960:X Chromosome / Q000235:genetics*
chemical_list: C507199:AMELX protein, human; D053523:Amelogenin; D003746:Dental Enamel Proteins