Is the rs10273639 C allele protective against pancreatitis?

The rs10273639 C allele at the PRSS1/PRSS2 locus is a well-studied genetic variant in the context of pancreatic health. However, current research indicates that the original claim reverses the actual relationship between this specific allele and disease risk.

Clinical and genetic evidence

Evidence from large-scale genetic studies and meta-analyses consistently demonstrates that the rs10273639 C allele is protective against pancreatitis, rather than a risk factor.

• Reduced Risk Profile: Meta-analysis data involving 1,462 acute pancreatitis patients and 3,999 controls found that the C allele is associated with a significantly reduced risk of the disease (OR 0.88, 95% CI 0.79–0.98). This protective effect is even more pronounced in alcoholic pancreatitis, with an odds ratio of 0.76 (95% CI 0.61–0.96).
• The T Allele as the Risk Factor: It is the T allele (and the presence of the TT genotype) that is linked to higher risk. The C allele, or the absence of the T allele, is associated with lower susceptibility to both acute and chronic forms of the disease.

Mechanistic explanations

The mechanism underlying the relationship between the PRSS1 locus and pancreatitis involves the "trypsin-driven injury pathway," but the C allele acts as a brake on this pathway rather than an accelerator.

• PRSS1 Expression: The rs10273639 C allele is in strong linkage disequilibrium with functional promoter variants (such as rs4726576) that decrease PRSS1 mRNA expression.
• Trypsinogen Regulation: By reducing the total amount of cationic trypsinogen produced, the C allele minimizes the pool of enzymes available for premature, accidental activation within the pancreas.
• Tissue Protection: Lower levels of intrapancreatic trypsin activation reduce the likelihood of acinar cell autodigestion, endoplasmic reticulum stress, and the subsequent inflammatory cascade that characterizes pancreatitis.

Progression to pancreatic insufficiency

While the original claim correctly identifies the long-term consequences of trypsin-driven injury, it misattributes the driver.

• Chronic Damage: It is well-established that recurrent pancreatic injury—driven by excessive trypsin activity (often seen in gain-of-function PRSS1 mutations like R122H)—leads to progressive fibrosis and the loss of functional acinar tissue.
• EPI Development: This chronic inflammation eventually results in exocrine pancreatic insufficiency (EPI). However, because the rs10273639 C allele reduces expression and protects against injury, it actually serves to lower the long-term risk of developing EPI.

Bottom line

The rs10273639 C allele is a protective variant that decreases PRSS1 expression and lowers the risk of pancreatitis. While the trypsin-driven pathway can lead to exocrine pancreatic insufficiency, the C allele helps prevent this progression by limiting the initial enzymatic injury.