Ichthyosis bullosa of Siemens (IBS) is an autosomal dominant disorder of keratinization. It is characterized by a mild epidermolytic ichthyosis which tends to localize to the flexures. Affected individuals are born with widespread blistering, which develops into large hyperkeratotic plaques over the extremities. Mutations in the K2e gene cause epidermolytic hyperkeratosis confined to the upper spinous and granular layers, as observed in IBS. In this report, we describe a novel mutation in the keratin 2e gene in a four-generation IBS kindred of German ancestry. The mutation resides within the 2B helix termination motif of the keratin 2e gene, and extends the body of evidence implicating keratin 2e gene mutations in IBS.