title: MDR1 gene: susceptibility in Spanish Crohn's disease and ulcerative colitis patients.
abstract: BACKGROUND
  The multidrug resistance MDR1 gene codes for a membrane transporter associated with inflammatory bowel disease. The polymorphism Ala893Ser/Thr (G2677T/A) previously showed significant association with Crohn's disease (CD) and the Ile1145Ile (C3435T) with ulcerative colitis (UC). We studied the association of both polymorphisms in an independent population to reveal the impact of the MDR1 gene on predisposition to inflammatory bowel disease.
  
  
  METHODS
  Case-control study with 321 CD and 330 UC white Spanish patients recruited from the same center, and 352 healthy ethnically matched controls.
  
  
  RESULTS
  A significant association of MDR1 C3435T with CD was observed (CC vs (CT + TT): P = 0.007; OR [95% CI] = 1.58 [1.12-2.23]). A CD susceptibility haplotype 2677T/C3435 was identified. No difference between UC patients as a whole and controls could be detected.
  
  
  CONCLUSIONS
  New evidence supports the role of the MDR1 gene on CD susceptibility. Therefore, considering our results and those from others, the MDR1 gene behaves as a common risk factor for both CD and UC. We discovered that the C3435 allele conferring susceptibility to CD is different from the described 3435T UC risk allele.
authors.affiliation: Department of Clinical Immunology, Hospital Clinico San Carlos, Madrid, Spain. eurcelay@hcsc.es
authors.forename: Elena
authors.initials: E
authors.lastname: Urcelay
authors.forename: Juan L
authors.initials: JL
authors.lastname: Mendoza
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Martín
authors.forename: Ana
authors.initials: A
authors.lastname: Mas
authors.forename: Alfonso
authors.initials: A
authors.lastname: Martínez
authors.forename: Carlos
authors.initials: C
authors.lastname: Taxonera
authors.forename: Miguel
authors.initials: M
authors.lastname: Fernandez-Arquero
authors.forename: Manuel
authors.initials: M
authors.lastname: Díaz-Rubio
authors.forename: Emilio G
authors.initials: EG
authors.lastname: de la  Concha
mesh_terms: D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000235:genetics*; D003424:Crohn Disease / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D019450:Genes, MDR; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D020641:Polymorphism, Single Nucleotide; D013030:Spain; D044465:White People