Epidermolysis Bullosa, Late-Onset Localized Junctional, With Mental Retardation

The various forms of epidermolysis bullosa can be classified into 3 major histologic groups: epidermolytic, junctional, and dermolytic. Distribution of lesions, extracutaneous manifestations, age of onset, and inheritance further divide these types into many subtypes. Nakar et al. (1992) described a brother and sister, born of healthy Bulgarian Jewish parents with no known consanguinity, who had late-onset epidermolysis bullosa localized to the anterior aspect of the legs associated with a defect of the dental enamel, dystrophic toenails, and mental retardation. Subluxation of the lenses was found in the only patient in whom complete ophthalmologic examination was performed. Both had a similar facial appearance including short midface and philtrum, prognathism, and thin vermilion border of the upper lip. The girl was born with a cleft palate. There was no homocystinuria. The skin lesions began at ages 7 and 9 years. The blistering lesions recurred especially in warm humid weather. A few blisters also appeared on the dorsal aspects of the hands and forearms. Reports suggesting the existence of an autosomal recessive form of epidermolysis bullosa were provided by Heagerty et al. (1985), Gamborg Nielsen and Sjolund (1985), and Niemi et al. (1988). The school-age onset of skin blistering apparently of junctional type, associated with enamel defect and nail dystrophy, were features identical to those in the female offspring of first-cousin parents reported by Anton-Lamprecht and Schnyder (1979). The histopathologic findings suggested degeneration of the basal layer with a subepidermal split and subepidermal bulla formation. The family reported by Niemi et al. (1988) appears to be different because of the associated muscular dystrophy and possibly more severe skin disease (see 226670).