ABSTRACT
INTRODUCTION Progress in molecular dermatology has over the past two decades reached several milestones in terms of identification of candidate genes and underlying pathogenic mutations in heritable skin diseases. In fact, the molecular genetics of as many as 300 single-gene skin disorders have been clarified by the identification of mutant alleles. At the same time, identification of the underlying genes in complex traits in which the intrinsic abnormalities often involve the genome-environment interface has been more difficult than perhaps initially anticipated.
