Laryngo-onycho-cutaneous syndrome

Laryngo-onycho-cutaneous (LOC) syndrome, also known as Shabbir syndrome, is an extremely rare autosomal recessive disorder that belongs to the group of junctional epidermolysis bullosa subtypes. It is caused by mutations in the LAMA3 gene, which encodes the alpha-3 chain of laminin-332, a critical protein involved in anchoring the epidermis to the underlying dermis. The condition was first described in families of Punjabi Muslim origin, though cases have since been identified in other populations. LOC syndrome primarily affects the skin, nails, eyes, and larynx. Key clinical features include the development of granulation tissue (excessive wound-healing tissue) in the larynx, conjunctiva, and skin, which can be progressive and debilitating. Affected individuals typically present in infancy or early childhood with hoarse cry or stridor due to laryngeal granulation tissue, nail dystrophy or absence of nails (anonychia), and cutaneous erosions that heal with granulation tissue rather than normal scarring. Ocular involvement includes conjunctival granulation tissue that can lead to corneal damage and vision impairment. Dental enamel defects may also be present. There is currently no cure for LOC syndrome. Treatment is supportive and symptomatic, focusing on wound care, management of airway complications (which may require tracheostomy in severe cases), ophthalmologic care to preserve vision, and nutritional support. The prognosis is variable but can be severe, with significant morbidity related to progressive granulation tissue formation, particularly in the airway and eyes. Early multidisciplinary management involving dermatology, otolaryngology, ophthalmology, and genetics is essential for optimizing outcomes.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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