A new mutation in the linker 12 domain of keratin 5 in a Chinese family with Weber-Cockayne epidermolysis bullosa simplex

A Novel Mutation p.L461P in KRT5 Causing Localized Epidermolysis Bullosa Simplex

Background

Epidermolysis bullosa (EB) is a rare genetic disease with widely different clinical manifestations, but the relationship between genotype and phenotype is not fully understood. In the present study, we recruited a Chinese family in which two members had been diagnosed with localized EB simplex (EBS), with clinical manifestation, including blisters and erosions on the soles of the feet since infancy.

Objective

To identify and confirm the genetic variation in a Chinese family diagnosed as localized EBS.

Methods

Our study included two patients, other healthy members of the family, and 100 normal controls. Genomic DNA samples were isolated from each participant, and then polymerase chain reaction (PCR) direct sequencing was performed.

Results

The results of PCR direct sequencing revealed a novel heterozygous missense mutation in codon 461 of exon 7 of KRT5 (c.1382T>C), which led to an amino acid change (p.L461P) in the patients with EBS but was absent in unaffected family members and 100 unrelated control samples.

Conclusion

The present study broadens the mutational spectrum of EBS, and this knowledge could be harnessed for prenatal screening, gene diagnosis, and gene therapy for localized EBS.

Novel mutation (Asp158Val) in H1 domain of keratin 5 gene in a Japanese patient with Köbner-type epidermolysis bullosa simplex

We describe a 19-year-old Japanese male with Köbner-type epidermolysis bullosa simplex (EBS-KB) with a novel keratin gene mutation. The patient developed blisters on the feet, palms, elbows and knees soon after birth. His father is similarly affected with blistering, but his mother and younger brother are not affected. Histological examination revealed that the primary separation in the blister occurred within the basal cell layer. Sequence analysis demonstrated an A-to-T transition at the second position of codon 158 in the keratin 5 (K5) gene. The amino acid at codon 158 was deduced to have changed from asparagine to valine. We identified a novel mutation (Asp158Val) in the H1 domain of the K5 gene in this Japanese patient with EBS-KB. This is the first gene mutation report of EBS-KB in the H1 domain of the K5 gene.