[Prenatal diagnosis of lethal junctional epidermolysis bullosa by fetal skin biopsy].

A 22-year-old woman, whose first infant had died of lethal junctional epidermolysis bullosa (JEB), requested prenatal diagnosis for her third pregnancy. At 20 weeks gestation, fetal biopsy was performed under direct vision by fetoscopy. A semithin section of epon-embedded skin showed dermo-epidermal separation at the light microscopic level. Electron microscopy revealed the site of separation to be within the lamina lucida of the epidermal basement membrane (EBM). Indirect immunofluorescence on a 5 microns cryostat specimen of skin showed a complete absence of GB3 monoclonal antibody immunostaining at the EBM compared with a control 18 week old normal fetal skin sample. The diagnosis was therefore made that the fetus was affected with lethal JEB and a prostaglandin termination performed. The diagnosis was confirmed by further studies on the aborted fetus. 54 cases of prenatal diagnosis of various types of epidermolysis bullosa performed at Institute of Dermatology over the last 10 years are briefly reviewed. Several social and practical problems to launch prenatal diagnosis in Japan are also discussed.