Junctional epidermolysis bullosa

PhD ceremony: Ms. W.Y. Yuen, 12.45 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Junctional epidermolysis bullosa

Promotor(s): prof. M.F. Jonkman, prof. R.J. Sinke

Faculty: Medical Sciences

They are called "Butterfly Children", the patients with epidermolysis bullosa (EB) with a skin as fragile as the wings of a butterfly. Approximately 25 distinct types of EB have been identified, which are caused by mutations in one of the 15 genes that are known to be involved. Junctional epidermolysis bullosa (JEB) is an EB type characterized by a cleavage through the junctional layer between the epidermis and dermis. The adhesion proteins in the junctional layer are disturbed or absent.

In the subtype JEB, type Herlitz (JEB-H) laminin-332 is totally absent. Children with JEB-H do not grow and suffer from painful erosions on their entire skin and in their throat. JEB-H is associated with hopeless, unbearable suffering and is fatal within the first 3 years of life. Twenty-two children with JEB-H were guided by the Center for Blistering Diseases in the UMCG from 1988 to 2011. This thesis presents the diagnostic features and long-term follow-up of these patients. We also interviewed parents who had lost their child to lethal EB, on which we based guidelines for the guidance of future parents. In one of the children, the parents asked for euthanasia, which was performed according to the Groningen protocol.

Another part of this thesis focuses on the less severe subtype JEB, type non-Herlitz (JEB-nH), in which patients do survive to adulthood. We showed that adult JEB-nH patients have -from an early age on- an increased risk (25%) of developing an aggressive squamous cell carcinoma that metastasizes in 20% of the patients. Another study describes that punch grafting, in which small skin grafts are placed in chronic wounds to promote wound healing, is an easy and effective treatment in JEB-nH patients. Furthermore, we show that JEB of late onset is caused by mutations in the gene COL17A1.