학술논문

Escape of the yolk sac: a hypothesis to explain the embryogenesis of gastroschisis
Document Type
Academic Journal
Source
Clinical Genetics. Apr 01, 2009 75(4):326-333
Subject
Language
English
ISSN
0009-9163
Abstract
Stevenson RE, Rogers RC, Chandler JC, Gauderer MWL, Hunter AGW. Escape of the yolk sac: a hypothesis to explain the embryogenesis of gastroschisis.Clin Genet 2009: 75: 326–333. © Blackwell Munksgaard, 2009Gastroschisis is a significant birth defect that in many countries has shown an increased prevalence in recent decades, and the change has affected primarily younger mothers. Despite numerous epidemiological studies no other consistent associated risk factor has been identified. In this paper we review the five main theories related to the pathogenesis of this malformation and outline the reasons why we think none fully explains the embryogenesis of gastroschisis. We briefly present some clinical observations we have made that we consider germane to the pathogenesis and outline a hypothesis that we think can account for the origins of this malformation. Our proposal is that the determining defect in gastroschisis is failure of the yolk sac and related vitelline structures to be incorporated into the umbilical stalk. Otherwise, ventral closure of the lateral abdominal walls occurs normally, thus orphaning the vitelline duct and yolk sac outside both the main body stalk and the abdominal wall. Thus, in addition to the umbilicus, the abdominal wall has a separate perforation through which the midpoint of the gut is attached to the exteriorized vitelline structures. This connection through the ventral wall prevents normal egress of the gut into the umbilical cord during the second month of development and acts as the egress point for the gut resulting in gastroschisis.