Epidemiology and Clinical Characteristics of Hirschsprung’s Disease

Hirschsprung’s disease (HSCR) is a relatively common cause of intestinal obstruction in the newborn. It is characterized by an absence of ganglion cells in the distal bowel beginning at the internal sphincter and extending proximally for varying distances. In the human fetus, neural crest-derived neuroblasts first appear in the developing esophagus at 5 weeks of gestation and then migrate down to the anal canal in a craniocaudal direction during the 5th to the 12th week of gestation. The absence of ganglion cells in HSCR has been attributed to a failure of migration of neural crest cells. The earlier the arrest of migration, the longer the aganglionic segment is. The absence of ganglion cells results in absent peristalsis in the affected bowel and the development of functional intestinal obstruction. The incidence of HSCR is estimated to be approximately 1 in 5000 live births. Over 80% of patients produce clinical symptoms and are diagnosed in the neonatal period. Delayed passage of meconium is the cardinal symptom in neonates with HSCR. The majority of patients with HSCR are male, with a male-to-female ratio of 4:1. The male preponderance is less evident in long-segment HSCR, where the male-to-female ratio is 1.5–2:1. Genetic factors have been implicated in the etiology of HSCR. It is known that HSCR occurs in families. The incidence of familial cases in rectosigmoid HSCR varies from 3.6% to 7.8% in different series.