BACKGROUND: Chronic pancreatitis shows alterations in the trypsinogen gene (protease serine 1, PRSS1) in some individuals. The conversion of trypsinogen to trypsin in the pancreas is believed to be one of the causes of pancreatitis. This study was to identify the mutation of the PRSS1 gene in a Chinese patient with chronic pancreatitis and to analyze the clinical features of the disease. METHODS: In 6 patients with chronic pancreatitis and 120 normal controls, PRSS1 genes were ampliifed by the polymerase chain reaction and the products were analyzed by sequencing. RESULTS:Multisite mutations of PRSS1 were found in a patient with chronic pancreatitis. C to A mutation occurred in exon 3 of PRSS1, and T to A mutation in the same exon. These mutations were not found in normal controls or the patients with chronic pancreatitis. CONCLUSION:These are novel mutations in PRSS1. (Hepatobiliary Pancreat Dis Int 2008;7:331-332)