Desmoglein is a transmembrane glycoprotein component of desmosomes in vertebrate epithelial cells. Two of the three currently known desmogleins are the autoantigens of autoimmune skin blistering diseases, pemphigus vulgaris and pemphigus foliaceus, in which autoantibodies cause the loss of cell adhesion of keratinocytes with resultant blister formation. In this study, the genes for two autoantigens (DSG1 for pemphigus foliaceus and DSG3 for pemphigus vulgaris) were mapped on band q12 of human chromosome 18 by fluorescence in situ hybridization. Furthermore, both genes were localized on a 320-kb genomic fragment separated by pulsed-field gel electrophoresis. These results suggest the possibility of a cluster for the desmoglein gene family on chromosome 18.