X-linked amelogenesis imperfecta is a condition that affects dental enamel characterized by vertical banding of the enamel in heterozygous females in contrast with more uniform appearances in males. The clinical features of a family with amelogenesis imperfecta are described. The disease in this family has been shown to be unlinked to the amelogenin gene locus on the distal short arm of the X chromosome. It maps instead to a locus on the long arm of the X chromosome in the Xq22-q28 region. There was considerable variability in clinical features in affected females in this family in contrast with the more consistent findings in families linked to the amelogenin gene locus region.