title: NOD2 exonic variations in Iranian Crohn's disease patients.
abstract: OBJECTIVE
  The NOD2 gene is known to have a strong association with Crohn's disease, but different trends were reported in occurrence of NOD2 variants in distinct ethnicities. The aim of this study was to assess all exonic sequences of the NOD2 gene in Iranian Crohn's disease patients and healthy controls to identify any existing variation and evaluate their association with Crohn's disease.
  
  
  METHODS
  A total of 90 non-related Crohn's disease patients and 120 sex- and age-matched healthy controls of Iranian origin were enrolled in this study. The participants were referred to a tertiary center in a 2-year period (2006-2008). The exonic regions of the NOD2 gene were amplified by polymerase chain reaction and evaluated by direct sequencing.
  
  
  RESULTS
  A total of 21 sequence variations were identified among all exonic regions of the NOD2 gene, of which eight had an allele frequency of more than 5%. Eight new mutations (one in exon 2 and seven in exon 4) were observed. The three main variants (R702W, G908R, and 1007fs) showed allele frequencies of 13.3%, 2.2%, and 1.7%, respectively. Three new variations (P371T, A794P, and Q908H) and R702W mutation were significantly more frequent in Crohn's disease patients compared to controls.
  
  
  CONCLUSIONS
  Eight novel mutations were identified in the NOD2 exons, but the pathophysiological importance of these variants remains unclear. Iranian patients with their different genetic reservoirs may demonstrate some novel characteristics for disease susceptibility.
authors.affiliation: Research Center for Gastroenterology and Liver Diseases, Taleghani Hospital, Shahid Beheshti University, M.C., Yemen St., Velenjak, Tehran, Iran.
authors.forename: Nosratollah
authors.initials: N
authors.lastname: Naderi
authors.forename: Alma
authors.initials: A
authors.lastname: Farnood
authors.forename: Manijeh
authors.initials: M
authors.lastname: Habibi
authors.forename: Homayoun
authors.initials: H
authors.lastname: Zojaji
authors.forename: Hedieh
authors.initials: H
authors.lastname: Balaii
authors.forename: Farzad
authors.initials: F
authors.lastname: Firouzi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Chiani
authors.forename: Faramarz
authors.initials: F
authors.lastname: Derakhshan
authors.forename: Ali
authors.initials: A
authors.lastname: Tahami
authors.forename: Rahim
authors.initials: R
authors.lastname: Aghazadeh
authors.forename: Nasser Ebrahimi
authors.initials: NE
authors.lastname: Daryani
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zali
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D016022:Case-Control Studies; D019295:Computational Biology; D003424:Crohn Disease / Q000235:genetics*; D004252:DNA Mutational Analysis; D004587:Electrophoresis, Agar Gel; D005091:Exons / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics*; D055815:Young Adult
chemical_list: C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein