6.2　An Explanation for Why No Chronic Pancreatitis...

6.2　An Explanation for Why No Chronic Pancreatitis-Predisposing Variants in the PRSS2 Gene Have Ever Been Described

Anionic trypsinogen（encoded by PRSS2）is the second major and functional trypsinogen isoform in the human pancreatic juice after cationic trypsinogen（encoded by PRSS1）；the two trypsinogen isoforms share 89%similarity at the amino acid sequence level（Chen et al.2013b）.It has been something of a puzzle that no variants in the PRSS2 gene have ever been reported to predispose to chronic pancreatitis（Chen et al.1999；Idris et al.2005；Whitcomb et al.1996b；Witt et al.2006）.Recently，a plausible explanation was put forward to account for this（Jancso and Sahin-Tóth 2016）.Having compared CTRCrelated biochemical properties of anionic and cationic trypsinogens，these authors concluded that anionic trypsinogen is controlled by CTRC in such a manner that individual natural PRSS2 mutations could not render the mutant anionic trypsin stable enough to promote intra-pancreatic activation.(https://www.daowen.com)