A (CG C>CA C) single nucleotide substitution, a c.365~366GC>AT (CGC>CAT) gene conversion event in exon 3 of PRSS1 was also found to result in a R122H mutation. This imposes a serious concern on the genotyping of pancreatitis by a widely used polymerase chain reaction-restriction fragment length polymorphism assay, which could only detect the commonest c.365G>A variant. Materials and methods DNA samples containing either the known c.365G>A or c.365~366GC>AT variant in exon 3 of PRSS1 were used as positive controls to establish a denaturing high performance liquid chromatography (DHPLC) assay. Results DHPLC could readily discriminate the two known different mutational events resulting in the R122H mutation. More importantly, under the same experimental conditions, it identified a further mutational event that also occurs in the R122 primary autolysis site but results in a different amino acid substitution: c.364C>T (C GC>T GC; R122C). Conclusions A rapid, simple, and low-cost assay for detecting both the known and new mutations occuring in the R122 primary autolysis site of PRSS1 was established. In addition, the newly found R122C variant represents a likely pancreatitis-predisposing mutation."/>
Detection of three mutational events in exon 3 of PRSS1 resulting in a disruption of the R122 primary autolysis site of human cationic trypsinogen. Left panel: denaturing high performance liquid chromatography (DHPLC) profile of the mutant compared with the wild type sequence. Right panel: direct DNA sequencing of independently amplified polymerase chain reaction products. Mutations are indicated by arrows. A: c.365G>A(CGC>CAC; R122H); B: c.365~366GC>AT (CGC>CAT; R122H); C: c.364C>T (CGC>TGC; R122C). Refer to Table 1 for a summary of these mutational events.