In Reply.—Dr Shaw previously placed a strong argument in the literature for the common origin of omphalocele and gastroschisis. We would have more correctly represented his views if we had quoted him as saying that gastroschisis and omphalocele are the result of failed closure of the umbilical ring, rather than the stated "failed lateral splanchnic fold migration."
The striking clinical differences outlined in our article suggest differing causes (as allowed by Dr Shaw in his letter). If differing etiologies in either an omphalocele or gastroschisis are accepted, why not separate the resulting embryological events? In the absence of an appropriate animal model, the question remains one of failure of closure of the umbilical ring vs a separate and unique failure of migration of the lateral splanchnic fold (usually on the right side), thus resulting in gastroschisis.
Moore1 has recently reexamined gastroschisis and omphalocele. He does not attempt a