[Cutaneomucous hyalinosis in monozygotic twins].

Two Urbach-Wiethe disease cases in both univitelline twins sisters, 8 years old, are presented. Consanguinity is demonstrated in their parents and we consider this to be the second study of this type described in Spain and the first one in the world with such genetic features. We emphasize the early process apparition--just after birth--clinically characterised only by hoarseness. In consecutive years, both sisters developed varioliform scars on elbows, knees, and forehead and induration of lips on their mucous surface and palpebral margins. The histological and ultrastructural findings superposed in both patient--typical and confirmatory of the clinical picture--are commented as well as present histopathogenetic interpretations.