Ameloblastin gene polymorphisms in healthy Japanese

Ameloblastin is one of the extracellular matrix proteins in tooth enamel and may be responsible for autosomal amelogenesis imperfecta (AI), since it plays a significant role in enamel crystal growth. We investigated polymorphisms of the human ameloblastin gene by polymerase chain reaction, DNA sequencing and single-strand conformational polymorphism (SSCP) analysis using genomic DNA from 50 Japanese subjects with sound dentition. One single sequential trinucleotide deletion and 3 single-nucleotide polymorphisms (SNPs) were identified in the translated region. The nucleotide deletion results in the lack of an amino acid residue and 2 of the SNPs cause nonsynonymous substitutions of amino acid residues. These results provide important background information for the investigation of autosomal AI in Japanese patients.