This trial seeks to investigate the effect of skin grafts in five patients with Netherton's syndrome, a genetic condition where the patient’s skin becomes extremely dry and easily inflamed. In this study, the patient’s skin stem cells will be harvested and then genetically manipulated in the laboratory to correct the mutation (in the SPINK5 gene). These corrected cells will be cultured in the laboratory before being grafted to the patient, where it is hoped that the transplanted cells will produce the proteins lacking in the condition (LEKT1) and benefit the patient. The trial is being conducted at Great Ormond Street Children's Hospital in London. The trial is expected to finish in July 2016.