Review of Keratin Disorders

This chapter deals with disorders caused by mutations in genes that code for epithelial keratins, which are intermediate filament proteins that make up much of the cytoskeleton in simple as well as multilayered epithelia. Keratins exist as obligate heterodimers, and the dimers in turn assemble into filaments that form the intermediate filament network. As such, keratins have a major role in maintaining structural integrity of cells and tissues, in addition to emerging functions in signal transduction. Mutations in epithelial keratins cause a plethora of disorders that mostly manifest in the skin, as well as in hair and nails. The phenotypes are quite variable and their impact on patients ranges from mild inconvenience to life-altering handicaps. Proper care for and counselling of the patients depends on accurate diagnosis, which is increasingly based on molecular genetics rather than subtleties of clinical appearance. To date there are no specific treatments for any keratin disorder, but this may soon change as insight into the underlying biology grows.