Many faces of Hirschsprung's disease.

Hirschsprung's disease (HSCR) is the main genetic cause of functional intestinal obstruction with an incidence of 1/5000 live births. The etiology of HSCR is complex and is presumed to be a sex-influenced multifactorial disorder, with contributions from several genes. All the genes involved in HSCR are also involved with the early development of the enteric nervous system. HSCR is known to be associated with a chromosomal abnormality in 12 % of cases, and with other congenital anomalies in additional 18 % of cases. It is recommended that patients, including newborns, with HSCR undergo a careful assessment by a clinician trained in dysmorphology. Echocardiography, ultrasonography for urogenital malformations and skeletal x-rays should be routinely performed in cases with HSCR to rule out associated anomalies. HSCR associated with dysmorphic features or any additional systemic anomaly should prompt chromosomal studies. Genetic counseling should be provided to families of HSCR patients as the recurrence risk varies from 4 % to up to 50 % depending on whether it is non-syndromic or part of a specific syndrome.