Epidermolysis bullosa simplex is a group of blistering skin disorders caused by 
defects in one of the keratin genes, KRT5 and KRT14. Previously reported KRT5 
and KRT14 mutations are clustered in several hotspots, namely the rod ends of 
the 1A and 2B domains and in the non-helical linker region L12. Therefore, 
genomic KRT5 and KRT14 mutation analysis was initially limited to these 
hotspots. In this study we describe the screening of nine EBS patients for 
mutations in the hotspots. In two patients, with the Koebner and the 
Weber-Cockayne subtypes of epidermolysis bullosa simplex respectively, we could, 
however, not identify any mutation in one of the hotspot domains of KRT5 and 
KRT14. Therefore, it appeared to be necessary to screen the entire genes for 
mutations. For KRT5, a complete genomic mutation detection system was previously 
described. We now developed a complete genomic mutation detection system for 
KRT14. For the amplification of the KRT14 genes, we make use of restriction 
sites to exempt the keratin 14 pseudogene sequence from polymerase chain 
reaction amplification. Using the complete genomic mutation detection system for 
both KRT5 and KRT14, we identified four novel KRT5 mutations (IVS1-1G>C, K404E, 
A438D, E475K), two of which are outside the KRT5 hotspot domains, and three 
novel KRT14 mutations (IVS4+1G>A, L408M, L130P).