Objective: To use molecular genetics to establish the mode of inheritance in a family with amelogenesis imperfecta.
Materials and methods: The polymerase chain reaction was used to amplify exons of the amelogenin gene on the short arm of the X chromosome.
Results: A single base deletion mutation in exon 6 of the amelogenin gene was identified. This mutation was a single base deletion of a cytosine residue - 431delC - in codon 96 of exon 6, introducing a stop codon 30 codons downstream of the mutation in codon 126 of the exon.
Conclusion: The firm establishment of an X-linked mode of inheritance affects the genetic counselling for this family.