Pepsinogen C gene polymorphisms associated with gastric body ulcer

This study was aimed to investigate the association of restriction fragment length polymorphisms (RFLPs) for pepsinogen genes with peptic ulcer disease. Eighty unrelated controls, 61 patients with gastric ulcer, and 57 patients with duodenal ulcer were studied. No genetic polymorphisms for pepsinogen A were detected by EcoRI digestion in Japanese subjects but a 100 base pairs insertion-deletion RFLP for the pepsinogen C gene was observed. The allele frequencies of the large (3.6 kilobase EcoRI fragment) and the small fragment (3.5 kilobase EcoRI fragment) were 80.6% and 19.4% respectively in controls, 55.4% and 44.6% in patients with gastric body ulcer, 79.4% and 20.6% in patients with gastric angular ulcer, 71.4% and 28.6% in patients with gastric antral ulcer, and 75.4% and 24.6% in patients with duodenal ulcer. The allele frequency of the small fragment was significantly higher in patients with gastric body ulcer than in controls and in patients with gastric angular or antral ulcer. The genotypes which possessed the small fragment were significantly more frequent in patients with gastric body ulcer (78.4%) than in controls (33.8%) and in patients with gastric angular or antral ulcer (37.5%). These results suggest that there is a significant association between the genetic polymorphism at the pepsinogen C gene locus and gastric body ulcer, and that the pepsinogen C RFLP is a useful marker of the genetic predisposition to this disorder. These results also indicate genetic heterogeneity of gastric ulcer disease, and suggest that the pepsinogen C RFLP may be a useful subclinical marker to explain the differences in genetic aetiologies of gastric body ulcer and gastric angular or antral ulcer.