[Contribution to the question of keratodermia palmo-plantaris insularis et striata. The phenomenon of the focal character of phenotypic expression of the pathological gene (author's transl)].

Two siblings with symptoms of Keratodermia palmo-plantaris areata and striata are described. The late father had some inherited disease of the skin. Neither ophthalmologic system nor a defect of intelligence existed in these cases. In the first case aminoacids in the blood and urine were examined, but neither thyrosinaemia nor thyrosinuria was found. The clinical signs in the siblings differed, and this difference was dependent from environmental factors. The focal character of the phenotypic expression of the pathologic gen of this inherited abnormality as well as other inherited diseases has been stressed.