The revolutionary advances of molecular genetics have made it possible in recent years to map the genes and identify the gene products of numerous hereditary skin diseases. The number of newly recognized gene loci responsible for genodermatoses is increasing almost every week. In this review, the gene locations of approximately 200 genodermatoses, categorized into various nosological groups, are presented and their genes or gene products, if already known, are documented in a tabular form. In this way novel, etiologically oriented criteria of classification emerge. On the one hand, dissimilar phenotypes can be attributed to one single gene locus, and on the other hand some clinically uniform genodermatoses have to be assigned to a number of different gene loci. Moreover, this review shows for which phenotypes additional research is particularly needed because we know the gene loci but so far not the underlying genes or gene products.