Epidermolysis bullosa simplex with mottled pigmentation – mutation analysis proved the diagnosis in a four-generation pedigree

Epidermolysis bullosa simplex with mottled pigmentation (EBS-MP) is a rare variant of the basal form of EBS, characterized by mild intraepidermal blistering due to lysis of basal keratinocytes and with a progressive reticular hyperpigmentation on the trunk and extremities. A limited number of cases – to date twenty unrelated families – have been published from all over the world, including thirteen reports from Europe. We here report the first Hungarian case in a four generation pedigree with EBS-MP symptoms and prove the diagnosis by mutation analysis. A heterozygous p.Pro25Leu mutation in the first exon of KRT5, together with the heterozygous polymorphism p.Gly138Glu, was identified in all the five affected family members studied. Our report extends the limited number of EBS-MP cases and gives further evidence that KRT5 mutations are responsible for this rare phenotype.