Gastroschisis in successive siblings: further evidence of an acquired etiology.

In recent years, we have treated two families that had successive siblings with gastroschisis. In the first family, the delivery of their second child, a boy with gastroschisis, was followed 11 months later by the delivery of a girl also with gastroschisis. The mother admitted to use of tobacco, alcohol, and marijuana during both pregnancies; the father was the same for both children. In the other family, the second child was a boy with gastroschisis, and the third, born 6 years later, was also a boy with gastroschisis. The mother denied any use of tobacco, alcohol, or recreational drugs; these two boys had different fathers. Gastroschisis in siblings has been reported only rarely, and has been noted in both identical and dizygotic twins. Our second set of siblings is the first documented case involving paternity by different fathers. Although a genetic factor cannot be excluded completely, teratogenic factors operative through the mother seem most probable. In conjunction with other reports of "epidemics" of gastroschisis, these two families amid our own recent outbreak of gastroschisis strongly suggest that the teratogenic factors may be environmental.