Correlation between variation of the 3' region of the cagA gene in Helicobacter pylori and disease outcome in Japan

J Infect Dis. 2002 Dec 1;186(11):1621-30. doi: 10.1086/345374. Epub 2002 Nov 11.


Genetic diversity within the cag pathogenicity island (PAI) of Helicobacter pylori may have a modifying effect on the pathogenic potential of the infecting strain. The genetic structure of the cag PAI was examined in Japanese isolates. The composition and nucleotide sequences of the cag PAI were quite similar among strains; however, diversity between 2 cag genes (virB10 and cagA) was observed. The variety in the number of repetition of the 5-amino acid sequence R1 (EPIYA) in the 3' region of the cagA gene was identified. The frequencies of the genotypes that contained >4 R1 sequences were significantly higher in atrophic gastritis-causing strains than in duodenal ulcer-causing strains. One-third of strains with >4 R1 sequences were gastric cancer-causing strains. Although the cag PAI is conserved in H. pylori isolates in Japan, H. pylori infection with the cagA genotype with >4 R1 sequences may correlate with the pathogenesis of atrophic gastritis and gastric cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antigens, Bacterial*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Disease Progression
  • Female
  • Gastritis, Atrophic / microbiology*
  • Gastrointestinal Diseases / microbiology
  • Genetic Variation*
  • Helicobacter Infections / complications*
  • Helicobacter Infections / microbiology
  • Helicobacter pylori / genetics
  • Helicobacter pylori / pathogenicity*
  • Humans
  • Japan
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Stomach Neoplasms / microbiology*
  • Virulence


  • Antigens, Bacterial
  • Bacterial Proteins
  • cagA protein, Helicobacter pylori