Catechol-O-methyltransferase (COMT) gene variants and pain in chronic pancreatitis

Background: Pain is the major symptom of chronic pancreatitis. The role of genetics in pancreatic pain is unclear. Catechol-O-methyltransferase (COMT) regulates enkephalin levels and influences pain perception. The COMT gene contains functional polymorphisms that have been found to influence human pain perception. The aim of our study was to investigate COMT single-nucleotide polymorphisms (SNPs) and diplotypes in chronic pancreatitis patients and healthy controls. Methods: We genotyped four COMT gene SNPs: c.1-98A>G (rs6269), c.186C>T (p.=) (rs4633), c.408C>G (p.=) (rs4818) and c.472G>A (p.Val158Met) (rs4680) using a dual-colour discrimination assay in 240 chronic pancreatitis patients and 445 controls. We generated five diplotypes with a frequency >0.5% and compared prevalence between patients and controls. Results: There was no significant association between the SNPs in the COMT gene and chronic pancreatitis. The diplotype AT CA/ACCG was more prevalent in controls compared with patients (OR 0.48, 95% CI 0.24 to 0.93, p=0.03) where the most common diplotype GCGG/ATCA served as reference. However, after correction for multiple testing, this is not a significant difference. The distribution of other diplotypes was not significantly different between patients and controls. Conclusion: COMT SNPs and diplotypes are not associated with chronic pancreatitis. As a consequence, our results do not support a significant role for the COMT gene in chronic pancreatitis.