The condition is clinically apparent at birth. Skin blistering is generalized and healing can occur either with atrophic scars, sometimes accompanied by hypopigmentation or hyperpigmentation or, less commonly, with the formation of exuberant granulation tissue. Nail dystrophy or loss is a constant feature, focal keratoderma can develop over time. Progressive and permanent hair loss is frequently present, affecting the scalp, eyelashes and eyebrows; pubic and axillary hair are scant or do not fully develop. Mucosal lesions mainly affect the oral and nasal cavity, although there is considerable individual variability. Ocular involvement has been reported in some patients and comprises corneal erosions and scars, and, rarely, ectropion. The teeth regularly show enamel hypoplasia, leading to severe caries. Chronic anemia of multifactorial etiology, although of varying severity, is frequent and may be associated with a growth delay.
Generalized non-Herlitz junctional epidermolysis bullosa is caused by mutations in the COL17A1 (10q24.3) and LAMA3 (18q11.2), LAMB3 (1q32) and LAMC2 (1q25-q31) genes.
