Molecular Basis of Hirschsprung’s Disease and Other Congenital Enteric Neuropathies

The enteric nervous system (ENS) is a complex neural network that controls many essential functions in the gastrointestinal tract, including the regulation of intestinal peristalsis. Neural crest cells migrate, proliferate, and differentiate within the intestinal wall to give rise to the neurons and glial cells of the ENS. Failure of this process to occur normally during embryogenesis can lead to severe disorders of intestinal motility, the most common of which is Hirschsprung’s disease. Several proteins have been identified as being essential for normal ENS development, including members of the Ret and endothelin-3 signaling pathways. The analysis of transgenic mice harboring mutations in these critical genes has greatly enhanced our understanding of the molecular regulation of ENS development and of the etiology of intestinal aganglionosis. Building on this fundamental research, much has been learned recently about the genetics underlying the complex inheritance pattern of Hirschsprung’s disease. Continued progress in elucidating the molecular basis of normal and abnormal ENS development will greatly enhance our understanding of congenital enteric neuropathies and improve our ability to diagnose and treat children affected by these disabling conditions.