Aplasia cutis congenita in two sibs discordant for pyloric atresia.

We report two sibs who were the products of a consanguineous mating, and who had an extensive form of aplasia cutis congenita (ACC). In one of them the generalized skin disorder was manifested by slipping off of the epidermis and mucous membranes with the slightest trauma. This sib also had pyloric atresia and other congenital malformations. Two hypotheses are presented to explain the discordance between the siblings for the abnormalities other than the ACC. One hypothesis assumes varying degrees of severity of the same autosomal recessive disease. The second suggests linkage between the gene for ACC and the gene for an epidermolysis bullosa (EB)-like disorder and pyloric atresia. a recombination event involving the EB-pyloric atresia gene in one carrier parent would then lead to an offspring with only ACC. Prenatal diagnosis is suggested by monitoring alpha-fetoprotein levels in aminotic fluid.