Therapeutic gene delivery in severe genetic skin disease may require production of a uniformly corrected population of cells capable of regeneration of normal skin elements when returned to the host. To achieve this, we have used lamellar ichthyosis (LI), a disorder of epidermal differentiation recently associated with defects in keratinocyte transglutaminase (TGasel), as a prototype. We have used a high-efficiency retroviral delivery approach to uniformly restore normal levels of TGasel expression to primary keratinocytes from severely affected LI patients previously lacking TGasel. Delivered TGasel was correctly targeted to membrane association and restored patient cell transglutaminase activity levels to normal. Corrected primary LI patient keratinocytes also demonstrated restoration of previously defective involucrin cross-linking and in vitro measures of cornification to levels found in normal cells. These results indicate that efficient TGasel delivery to early passage keratinocytes can produce a population of corrected LI patient cells. The capability to produce such cells may provide a basis for future efforts at gene therapy for genetic skin disease.