title: Associations between genetic variants in the IRGM gene and inflammatory bowel diseases in the Korean population.
abstract: BACKGROUND
  Recent European ancestry genome-wide association studies have identified genetic variants of IRGM as significant susceptibility loci for Crohn's disease (CD). Therefore, we investigated whether genetic variants of IRGM confer genetic susceptibility to CD or ulcerative colitis (UC) and evaluated the genotype-phenotype associations in the Korean population.
  
  
  METHODS
  This study included 510 inflammatory bowel disease (IBD) patients (253 patients with CD and 257 with UC) and 520 healthy controls in Koreans. Initially, we performed direct sequencing analysis to identify unique IRGM single nucleotide polymorphisms (SNPs). Three selected haplotype-tagging SNPs and one risk locus (rs72553867, rs10065172, rs4958847, and rs12654043) within the IRGM were then geno-typed in patients and controls.
  
  
  RESULTS
  IRGM SNP rs10065172 was significantly associated with CD susceptibility in terms of allelic frequency (P = 0.004; odds ratio [OR] = 1.42) and genotype frequency (dominant model, P = 0.008; OR = 1.62). We also found a relationship between SNP rs72553867 and CD susceptibility in the analysis of allelic frequency (P = 0.0117; OR = 0.67) and genotype frequency (dominant model, P = 0.002; OR = 0.55). In addition, we observed that the association of CD with rs10065172 became stronger in patients with younger age at diagnosis (≤ 20 years) or male gender. However, there was no significant association between the four SNPs and UC susceptibility.
  
  
  CONCLUSIONS
  This is the first study to identify SNP rs10065172 and rs72553867 in IRGM as principal CD susceptibility loci in an Asian population.
authors.affiliation: Department of Internal Medicine, Graduate School, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Chang Mo
authors.initials: CM
authors.lastname: Moon
authors.forename: Dong-Jik
authors.initials: DJ
authors.lastname: Shin
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Nak-Hoon
authors.initials: NH
authors.lastname: Son
authors.forename: Ahram
authors.initials: A
authors.lastname: Park
authors.forename: Boram
authors.initials: B
authors.lastname: Park
authors.forename: Eun Suk
authors.initials: ES
authors.lastname: Jung
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Kim
authors.forename: Sung Pil
authors.initials: SP
authors.lastname: Hong
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Kim
authors.forename: Won Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Jae Hee
authors.initials: JH
authors.lastname: Cheon
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000235:genetics*; D003424:Crohn Disease / Q000453:epidemiology / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D019204:GTP-Binding Proteins / Q000235:genetics*; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011379:Prognosis; D056910:Republic of Korea / Q000453:epidemiology; D055815:Young Adult
chemical_list: D019204:GTP-Binding Proteins; C513539:IRGM protein, human