In a study by Coyle et al., neuronal nitric oxide synthase was found to be higher in the ganglionated bowel of patients with HSCR and reduced in the aganglionic segment compared to the bowel of patients without HSCR, while choline acetyltransferase was higher in aganglionic bowel and lower in ganglionated bowel compared to controls [5]. This evidence concerns the gene CHAT and Hirschsprung disease.