Genotype-oropharyngeal phenotype correlation in Mexican patients with dystrophic epidermolysis bullosa

Previous investigations have attempted to correlate the genotype with the cutaneous phenotype in patients with epidermolysis bullosa (EB), but never with the oropharyngeal phenotype. Seventeen dystrophic EB (DEB) patients were genotyped for COL7A1 gene mutations and divided into five distinct groups. Oropharyngeal disease severity was assessed with the Epidermolysis Bullosa Oropharyngeal Severity (EBOS) score by an oral medicine specialist. The genotype-phenotype correlation was calculated by Kruskal-Wallis analysis of variance using the Mann-Whitney test, applying the Bonferroni correction. The most severe oropharyngeal phenotype was found in the group with the 2470insG/3948insT mutation, with a mean disease severity score of 18.50 ± 2.12; the mildest was found in the 6862del16 mutation group, with a mean disease severity score of 0.57 ± 1.13. The most significant difference in median score was found in the total score (P = 0.009), followed by tongue (P = 0.02) and upper lip (P = 0.021), but no correlation was found between disease severity and the groups (P>0.005, after Bonferroni correction). Multiple comparisons among the five different genotypic groups revealed no statistically significant genotype-oropharyngeal phenotype correlation; it was not possible to establish which group was more severe, or to associate a specific mutation to a specific oropharyngeal phenotype.