The prevalence of epidermolysis bullosa simplex (EBS) is estimated to be approximately 6 to 30 per 1 million live births. The disease is usually caused by missense mutations in KRT5 and KRT14, encoding keratins mostly expressed in the epidermal basal layer. Major advances in understanding of the molecular basis of EBS and other keratin disorders have led to the development of DNA-based prenatal testing.