Editor,—We read with great interest the paper by Nishimori et al(Gut1999;44:259–263) that reported the presence of two cationic trypsinogen gene mutations, the N21I in exon 2 and the R117H in exon 3, in two Japanese families with hereditary pancreatitis. Furthermore, this report showed that these mutations are worldwide and that the defect in cationic trypsinogen is important in the pathogenesis of hereditary pancreatitis. However, these authors questioned whether the N21I mutation …