Editor—A g.133283G>A (nomenclature in accordance with Rowen et al 1) single base change in exon 3 of the cationic trypsinogen gene or T4, resulting in an Arg (CGC) to His (CAC) substitution at amino acid residue 122 (R122H, originally named R117H in the chymotrypsin numbering system; nomenclature discussed in detail in Chen and Ferec2) of the cationic pretrypsinogen, was shown to be associated with hereditary pancreatitis (HP, MIM 167800) in 1996.3 To date, this mutation has been shown to be the most frequent mutation in HP world wide.4-9 The occurrence of g.133283G>A could be attributable to a spontaneous deamination of 5-methylcytosine to give thymine in the CpG dinucleotides on the opposite strand.

In an effort to screen for possible cationic trypsinogen gene mutations in sporadic chronic pancreatitis, which was diagnosed on clinical features and pathological sonographic findings, we observed one altered migration pattern different from that of the g.133283G>A transition in exon …