A family is described in which eight cases of autosomal dominantly inherited keratodermia palmo-plantaris papulosa were found in three generations. The propositus and his brother suffered simultaneously from deuteranopia and deuteranomalia. The propositus was operated on for gastric and duodenal ulcers; his brother, as well as his eldest son, had radiologically confirmed duodenal ulcers. Moreover, some members of the family had different inherited anomalies. The significance of these signs is unknown. The definition of the concept of the focal character of phenotypic expression of the pathologic gene is given. According to our histologic and ultrastructural investigations, as well as our study of the available literature, keratodermia palmo-plantaris papulosa is a heterogeneous entity.