Genetic disorders may affect any cutaneous structure, from the defective ou
ter protective layers in the ichthyoses, to errors in the critical basement
membrane zone in epidermolysis bullosa, to the disordered dermal integrity
in Ehlers-Danlos syndrome. These and other important "genodermatoses" are
reviewed, with particular attention to cutaneous clues to their diagnosis.
The recent identification of the underlying molecular basis of all of these
genetic disorders allows prenatal diagnosis based on molecular diagnosis i
n families with identified gene mutations.