title: CARD15 and IL23R influences Crohn's disease susceptibility but not disease phenotype in a Brazilian population.
abstract: BACKGROUND
  Although many genetic variants are identified in association with Crohn's disease (CD), CARD15, IL23R, and ATG16L1 association with CD have been firmly confirmed in Caucasians of European ancestry. The prevalence of CD is rapidly rising in Brazil, where European ancestry is firmly admixed with natives and Africans, resulting in a heterogeneous population. We investigated the contribution of CARD15, IL23R, and ATG16L1 with CD risk in a heterogeneous Brazilian population.
  
  
  METHODS
  Genotyping for CARD15 (R702W, G908R, 3020insC), IL23R (rs1004819, rs7517847, rs11209026, rs10889677, rs1495965), and ATG16L1 (rs2241880) was performed in 187 children and adults with CD and 255 healthy ethnically matched controls. Clinical records were systematically reviewed and detailed phenotypic information was obtained.
  
  
  RESULTS
  At least 1 CARD15 risk allele was present in 30% of the CD patients compared with 10% of controls. Variants of CARD15 (3020insC and R702W) and IL23R (rs1004819, rs11209026, and rs1088967) were associated with CD. However, no genotype-phenotype correlations were found among the Brazilian CD population with CARD15 or IL23R variants. No significant association was achieved with ATG16L1.
  
  
  CONCLUSIONS
  CARD15 and IL23R confer susceptibility to CD in the Brazilian population. However, the presence of these variants did not influence disease phenotype. Further research should be focused on larger sample sizes with population admixture analysis to better understand the risks and genotype-phenotype correlation in populations like Brazil where the prevalence of CD is rapidly rising.
authors.affiliation: Department of Internal Medicine, Federal University of Paraná, Curitiba, PR. marcialbaptista@hotmail.com
authors.forename: Márcia Luiza
authors.initials: ML
authors.lastname: Baptista
authors.forename: Heda
authors.initials: H
authors.lastname: Amarante
authors.forename: Geraldo
authors.initials: G
authors.lastname: Picheth
authors.forename: Vera Lucia
authors.initials: VL
authors.lastname: Sdepanian
authors.forename: Nicholas
authors.initials: N
authors.lastname: Peterson
authors.forename: Umesh
authors.initials: U
authors.lastname: Babasukumar
authors.forename: Hermênio C
authors.initials: HC
authors.lastname: Lima
authors.forename: Subra
authors.initials: S
authors.lastname: Kugathasan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D000071183:Autophagy-Related Proteins; D001938:Brazil / Q000453:epidemiology; D002352:Carrier Proteins / Q000235:genetics; D002648:Child; D003424:Crohn Disease / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D015995:Prevalence; D018123:Receptors, Interleukin / Q000235:genetics* / Q000378:metabolism; D012189:Retrospective Studies
chemical_list: C518959:ATG16L1 protein, human; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; C515500:IL23R protein, human; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D018123:Receptors, Interleukin; D004247:DNA