Background/Aims Single-point mutations in the cationic trypsinogen gene have been reported in hereditary pancreatitis kindreds in the white population. The aim of the present study was to investigate whether similar gene mutations are present in Japanese hereditary pancreatitis kindreds.

Results Two types of single-point mutation in the cationic trypsinogen gene, which were identical with those reported in white families with hereditary pancreatitis, were observed in separate Japanese families with hereditary pancreatitis: ²¹Asn (AAC) to Ile (ATC) (N21I) in exon 2 and ¹¹⁷Arg (CGC) to His (CAC) (R117H) in exon 3. Pancreatitis occurred at more advanced ages in patients with the N21I mutation than in those with the R117H mutation. Besides normal polymorphisms in exons 4 and 5, no mutation was found in patients in the remaining four families with hereditary pancreatitis, 21 patients with sporadic chronic pancreatitis, or five normal subjects.

Conclusions These results show heterogeneity, but no racial specificity, in the cationic trypsinogen gene mutations in hereditary pancreatitis kindreds. A distinctive clinical feature for each of the mutation types is suggested: adult onset for the N21I mutation and childhood onset for the R117H mutation.