LOC syndrome is a subtype of junctional epidermolysis bullosa (JEB, see this term) characterized by an altered cry in the neonatal period and by aberrant production of granulation tissue in particular affecting the upper airway tract, conjunctiva and periungual/subungual sites.
Prevalence is unknown. Fewer than 50 cases have been reported to date, mostly in consanguineous families from the Punjabi region of Pakistan and India.
The condition is present at birth. Characteristic cutaneous findings are transient blisters leaving slowly healing erosions with exuberant granulation tissue formation, mainly localized to the head and neck, hands, feet, elbows and knees. Extracutaneous manifestations are always observed: the progressive laryngeal involvement frequently leads to fatal respiratory obstruction in infancy, and the chronic conjunctival lesions cause symblepharon formation, and also total palpebral occlusion and blindness. Enamel hypoplasia is also always present and nail dystrophies are common.
The condition is associated with mutations in the alpha-3 chain of laminin-332 (LAMA3).
LOC syndrome follows an autosomal recessive pattern of inheritance.
Prognosis is poor.
Last update: October 2012