BACKGROUND/PURPOSE: Hirschsprung disease (HSCR) is a congenital disorder 
characterized by the absence of intramural ganglion cells along with variable 
lengths of the gastrointestinal tract. Recent studies have indicated the 
potential function of neuregulin-1 (NRG1) in HSCR, which encodes the heregulins 
and other mitogenic ligands for the ErbB family. The purpose of this study was 
to further clarify the role of NRG1 in the pathogenesis of HSCR.
METHODS: We examined the NRG1 messenger RNA (messenger RNA) and protein 
expression levels in gut tissues of 63 patients with sporadic HSCR (both 
stenotic and dilated gut tissues) and 35 controls. Moreover, using the 
methylation-specific polymerase chain reaction, we examined the methylation 
pattern of exon 1 of the NRG1 gene.
RESULTS: The mRNA expression levels of NRG1 were significantly higher in tissues 
of HSCR than those in controls, and the increased NRG1 protein levels in HSCR 
were consistent with the mRNA levels. However, no methylation pattern change was 
observed in exon 1 of the gene among different groups.
CONCLUSIONS: Our study demonstrates that the aberrant expression of NRG1 may 
play an important role in the pathology of HSCR. DNA methylation of the gene 
seems not to be involved in the mechanism of such aberrant expression, and other 
factors should be explored.