Hair follicle-specific keratins and their diseases

The human keratin family included 54 members, with 28 type I and 26 type II keratins. Among these, 26 keratins were specific to hair follicles, nearly equal to the 28 keratins expressed in various epithelia. More than half of the epithelial keratins were linked to inherited diseases, with type I and type II mutations being equally responsible. However, only 5 out of the 26 hair follicle-specific keratins were associated with inherited hair disorders, and one keratin acted as a risk factor. All hair follicle-specific keratins involved in pathologies were type II keratins. The document detailed hair diseases caused by mutations in hair keratins, such as monilethrix and ectodermal dysplasia of hair and nail type, and hair follicle-specific epithelial keratins, including two mouse models (RCO3 and CaRin) and pseudofolliculitis barbae.