Key points from article :
Junctional epidermolysis bullosa DNA lacks the instructions to stick epidermis to the dermis.
Genetic disease leaves skin as fragile as a butterfly's wings.
4 sq cm patch of skin was taken and its DNA repaired in the laboratory.
Genetically modified skin cells were grown to make skin grafts totalling 0.85 sq m.
After 21 months skin is functioning normally with no sign of blistering.
The study was published in the Nature journal.
