GENETIC-HETEROGENEITY OF COMBINED GASTRIC AND DUODENAL-ULCERS DETECTED BY PEPSINOGEN-C GENE POLYMORPHISM

It has been reported recently that there was genetic heterogeneity in gastric ulcer disease depending upon the location of the ulcer, and th at there was a significant association between the restriction fragmen t length polymorphism (RFLP) for pepsinogen C (PGC) gene and gastric b ody ulcer. In the present study, the association of the RFLP for PGC g ene with combined gastric and duodenal ulcers was investigated to anal yse genetic factors in its aetiology. Eighty unrelated controls and 47 patients with combined gastric and duodenal ulcers were studied. The allele frequencies of the large (3.6 kilobase EcoRI fragment) and the small fragment (3.5 kilobase EcoRI fragment) were, respectively 80.6 a nd 19.4% in controls, 60.0 and 40.0% in patients with combined gastric body and duodenal ulcers, 69.0 and 31.0% in patients with combined ga stric angular and duodenal ulcers, and 81.8 and 18.2% in patients with combined gastric antral and duodenal ulcers. The allele frequency of the small fragment was significantly higher in patients with combined gastric body and duodenal ulcers than in controls. The genotypes that possessed the small fragment were significantly more frequent in patie nts with combined gastric body and duodenal ulcers (66.7%) than in con trols (33.8%) and combined gastric antral and duodenal ulcers (27.3%). These results suggest that there is genetic heterogeneity in combined gastric and duodenal ulcers depending upon the location of gastric ul cer, and that combined gastric body and duodenal ulcers are associated with the small fragment allele of the PGC RFLP in the same way as sol itary gastric body ulcers.