7 Natural Gene Therapy: Revertant Mosaicism
One remarkable clinical observation has been that some individuals with RDEB acquire patches of skin that are more resistant to trauma and tend not to blister (Fig. 3), and which show increased expression of C7 and restoration of anchoring fibrils.[26,27] This phenomenon, termed revertant mosaicism (or natural gene therapy), results from several possible corrective genetic events and has been observed in several other inherited skin diseases.[28,29] Revertant mosaicism is likely to be more common than is currently appreciated and indeed perhaps all patients with non-Herlitz junctional EB may display clinical evidence of this type of reversion.[30,31] An important question has been how best to exploit this natural phenomenon to help patients? Initial attempts to expand revertant keratinocytes from a patient with non-Herlitz junctional EB in culture and then skin grafting were not successful, mostly because the degree of reversion was not maintained in culture over mutant cells, but punch grafting of revertant skin in another patient to unreverted areas has led to clinical and functional improvement with maintenance of reversion in the both the donor and recipient sites.
Am J Clin Dermatol. 2014;15(1):1-6. © 2014 Adis Springer International Publishing AG