The frequency of PD was higher in patients with CFTR gene-associated pancreatitis as compared with those with idiopathic and alcoholic pancreatitis (P<0.0001) and with those with SPINK1 and PRSS1 gene-associated pancreatitis (P<0.02).
This problematic trend is notably illustrated by two recent studies that classified the p.A121TPRSS1 variant as pancreatitis associated, in large part owing to its intimate proximity to arginine-122, the residue affected by the disease causing p.R122H mutation.
Over the past 5 years, several gain-of-function missense mutations in the human cationic trypsinogen gene (PRSS1, OMIM 276000) have been associated with hereditary and/or sporadic pancreatitis.
Mice that express PRSS1<sup>R122H</sup> developed more severe pancreatitis after ethanol feeding or a high-fat diet than mice that express PRSS1 or control mice.
Alcohol was long thought to be the primary causative agent, but genetic contributions have been of interest since the discovery that rare PRSS1, CFTR and SPINK1 variants were associated with pancreatitis risk.
Inclusion criteria were the presence of mutation in the cationic trypsingen gene (PRSS1 gene), or chronic pancreatitis in at least two first-degree relatives, or three second-degree relatives, in the absence of precipitating factors for pancreatitis.
A model of interactions between environmental triggers of pancreatic inflammation and disease susceptibility or modifying genes (including PRSS1, SPINK1 and CFTR) provides a framework within which to understand disease pathogenesis.
We investigated 78 patients with hereditary and familial pancreatitis and 62 patients with sporadic pancreatitis that were tested negative forcationic trypsinogen gene mutations, and 73 controls.
Relative expression of: (a) the PRSS1 R122 and H122 alleles; and (b) the PRSS1 and SPINK1 genes in pancreatitis were determined using complementary methods.
Previous studies have shown an association of variants in trypsin-associated genes, such as cationic trypsinogen (PRSS1) and serine protease inhibitor, Kazal type-1 (SPINK1) with pancreatitis.
Children with PD were less likely to have PRSS1 mutations (10% vs. 34%; P<0.01) or a family history of pancreatitis (P<0.05), and more likely to have hypertriglyceridemia (11% vs. 3%; P=0.03).
The strong association of mutations in the PRSS1 gene and in the SPINKI gene with chronic pancreatitis supports the concept of intracellular trypsin activation as an initiating and extremely important step in the development of pancreatitis.
A review of the ongoing hereditary pancreatitis study of the Midwest Multicenter Pancreatic Study Group suggests that the risk of pancreatic cancer is related to long-standing pancreatitis rather than to the cationic trypsinogen mutations.
Having found a nonsense mutation (c.111C>A; Y37X) and a splicing mutation (IVS2+1G>A) in the cationic trypsinogen gene (protease, serine, 1; PRSS1) in alcoholics without the development of CP, but not in alcoholics with CP and patients with hereditary or idiopathic CP, we propose that while "gain of function" mutations in the PRSS1 gene predispose one to pancreatitis, "loss of function" mutations in the gene may protect one against the disease.
We performed sequence analysis of the cationic trypsinogen-coding region in 46 alcohol-related pancreatitis patients and 16 patients with pancreatitis due to causes other than alcohol.