The epidermal differentiation complex (EDC) is a gene complex comprising over fifty genes encoding proteins involved in the terminal differentiation and cornification of keratinocytes, the primary cell type of the epidermis. In humans, the complex is located on a 1.9 Mbp stretch within chromosome 1q21.[1][2] The proteins encoded by EDC genes are closely related in terms of function, and evolutionarily they belong to three distinct gene families: the cornified envelope precursor family, the S100 protein family and the S100 fused type protein (SFTP) family.[3]
It has been hypothesized that the clustering of EDC genes occurred due to duplication events which were evolutionarily favored during the adaptation to terrestrial environments.[3][4] In sirenians, the main subtypes of EDC genes have been conserved or even duplicated, such as the duplicated late cornified envelope genes of dugongs. On the other hand, FLG genes of the SFTP family have become inactivated in sirenians, with the exception of manatees. Cetaceans have also lost function of FLG genes.[5] EDC proteins have been involved in a variety of skin disorders including ichthyosis vulgaris, atopic dermatitis and psoriasis.[6]
^Volz, Armin; Korge, Bernhard P.; Compton, John G.; Ziegler, Andreas; Steinert, Peter M.; Mischke, Dietmar (October 1993). "Physical Mapping of a Functional Cluster of Epidermal Differentiation Genes on Chromosome 1q21". Genomics. 18 (1): 92–99. doi:10.1006/geno.1993.1430. PMID8276421.
^Hoffjan, S; Stemmler, S (September 2007). "On the role of the epidermal differentiation complex in ichthyosis vulgaris, atopic dermatitis and psoriasis". British Journal of Dermatology. 157 (3): 441–449. doi:10.1111/j.1365-2133.2007.07999.x. PMID17573887. S2CID9434345.