Novel KRT14 mutation causing epidermolysis bullosa simplex with variable phenotype.

[epidermolysis bullosa simplex]

About 75 % of cases of epidermolysis bullosa simplex result from mutations in KRT 5 and KRT 14 genes . Here , we report a family with a novel heterozygous missense mutation p .Leu 418 Gln in the KRT 14 gene causing EBS of phenotype varying from EBS-loc to EBS -gen intermed . To the best of our knowledge , the family reported by us is the largest one in which two different phenotypes can be distinguished . The molecular dynamics simulations show that p .Leu 418 Gln mutation results in clear disruption of intermolecular π-stacking between KRT 14 :Tyr 415 and KRT 5 :Tyr 470 , which in turn may affect putative phosphorylation site at KRT 14 :Thr 414 . This study further supports the importance of the EIATYR /KLLEGE motif in maintaining structural stability of KRT 14 :KRT 5 heterodimer and indicates that physical properties of introduced amino acid can modulate the disease severity . The results obtained indicate further need of genotype-phenotype studies in EBS . In conclusion , genotype-based prognosis should be given to patients with caution .