The natural history of laryngo-onycho-cutaneous syndrome: A case series of six pediatric patients and literature review.

BACKGROUND/OBJECTIVES: Laryngo-onycho-cutaneous syndrome (LOC) is a rare subtype of junctional epidermolysis bullosa (JEB), featuring aberrant granulation tissue formation in the skin, larynx, and eyes. So far, three mutations including the specific (founder) mutation in exon 39 of LAMA3 (c.151dup) have been identified, but sparse data exists regarding the natural history, the genotype-phenotype correlation, and its differentiation from other JEB types. METHODS: We reviewed our pediatric EB database to identify English children with clinical and genetically diagnosed LOC within the last 15 years. Their demographic, clinical, and laboratory data were examined. We searched three databases for case reports of LOC between January 1986 and November 2020 and extracted clinical and molecular details. RESULTS: We identified 6 LOC patients, all female (mean age 5.4 years). Periungual hypergranulation and skin fragility were the earliest presenting signs (0-3 months), followed by laryngeal stenosis, symblepharon (mean onset 10.7 and 11.8 months, respectively), and dental abnormalities. Five children developed anemia at an average of 19.2 months. We identified 22 published studies in English with 31 cases. CONCLUSIONS: This study delineates the disease course of LOC and highlights the overlap with some forms of JEB. Classical signs/symptoms including anemia appear early in life. Genetic analysis revealed three new LOC-associated variants and underscores the finding that interpretation of skin immunolabeling and molecular diagnostics can be challenging. We provide recommendations on management of this complex syndrome.

[Dental alterations in junctional epidermolysis bullosa--report of a patient with a mutation in the LAMB3-gene]. / Zahnveränderungen bei junktionaler Epidermolysis bullosa-- Bericht über eine Patientin mit einer Mutation im LAMB3-Gen.

During early odontogenesis the basement membrane is known to be important in epithelio-mesenchymal interactions. Mutations in the gene of one of the major structural proteins of the basement membrane such as laminin 5 might therefore be expected either to seriously compromise ameloblast differentiation and/ or interfere with normal basement-membrane formation and degradation and thus the binding of the ameloblasts to their underlying matrix. Teeth of patients suffering from junctional epidermolysis bullosa (JEB) can be severely affected by abnormal dental development and generalized or focal enamel hypoplasia. Those changes are found in 100% of individuals with JEB but the expression is variable. Beside the quantitative alterations, changes in the prismatic structure and orientation of enamel crystals are described. In addition JEB is associated with an increased risk for dental caries, caused by developmentally compromised enamel and external factors such as difficulties in maintaining oral hygiene because of oral lesions or a softer and more refined high caloric diet. Dental care includes three main strategies: Prevention by consequent oral hygiene and reduction of cariogenic nutrition is of paramount importance to minimize caries development; the restoration of enamel and dentin defects with fillings and stainless steel crowns to guarantee structure and function of teeth; and extractions of most severely affected teeth with osteolytic foci to remove continuous sources of oral infections.