title: [Relationship between gene polymorphisms in MMP-9 and Helicobacter pylori-related upper gastrointestinal disease in children].
abstract: OBJECTIVE
  To investigate the relationship of the promoter of matrix metalloproteinase-9 (MMP-9) gene polymorphisms with the susceptibility and clinical features of Helicobacter pylori (H. pylori)-related chronic gastritis and duodenal ulcer in children.
  
  
  METHODS
  One hundred children with chronic gastritis, 32 children with duodenal ulcer and 102 healthy children were enrolled.The promoter of MMP-9-1562C/T gene polymorphisms were genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and sequencing. MMP-9 mRNA expression in gastric mucosa was confirmed by reverse transcription polymerase chain reaction.
  
  
  RESULTS
  The genotype distributions and allele frequencies of MMP-9-1562C/T gene polymorphisms were similar in gastric upper gastrointestinal disease and healthy subjects. The relative risk for H.pylori infection in C/C genetype carriers was 3.1 times as high as that in T allele (C/T+T/T) carriers in children with chronic gastritis. MMP-9-1562 C/T gene polymorphisms did not affect MMP-9 mRNA expression level.
  
  
  CONCLUSIONS
  These data suggest that MMP-9-1562 C/T gene polymorphisms are not associated with susceptibility to chronic gastritis and duodenal ulcer in children. The C/C genotype of MMP-9-1562 C/T gene polymorphism might be associated with H.pylori infection.
authors.affiliation: Department of Pediatrics, First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China. shanqw333@yahoo.com.cn
authors.forename: Qing-Wen
authors.initials: QW
authors.lastname: Shan
authors.forename: Cheng-Xue
authors.initials: CX
authors.lastname: Jing
authors.forename: Lin-Lin
authors.initials: LL
authors.lastname: Wang
authors.forename: Zi-Li
authors.initials: ZL
authors.lastname: Lu
authors.forename: Qing
authors.initials: Q
authors.lastname: Tang
authors.forename: Xiang
authors.initials: X
authors.lastname: Yun
authors.forename: Shu-Jun
authors.initials: SJ
authors.lastname: Lian
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D004381:Duodenal Ulcer / Q000209:etiology / Q000235:genetics*; D005260:Female; D005756:Gastritis / Q000209:etiology / Q000235:genetics*; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D020780:Matrix Metalloproteinase 9