A premature stop codon mutation in the 2B helix termination peptide of keratin 5 in a German epidermolysis bullosa simplex Dowling-Meara case

Epidermolysis bullosa simplex (EBS) is caused by defective assembly of kera tin intermediate filaments in basal keratinocytes and recent studies indica ted causal mutations in the keratin KRT5 and KRT14 genes. In this study, we describe a novel KRT5 mutation in a German sporadic case of EBS Dowling-Me ara. Transition of G to T (nucleotide position 2334) leads to a premature s top codon (E477stop, residue 93 of the 2B helix) in the last residue of the highly conserved helix-termination peptide K/LLEGE of the 2B rod domain of keratin K5. This represents the first premature stop codon mutation identi fied within the K/LLEGE motif of any disorder reported so far that is cause d by keratin mutations.