IBD1 and IBD3 determine location of Crohn's disease in the Spanish population.
BACKGROUND
Crohn's disease is a heterogeneous disease from both genetic and clinical points of view.


OBJECTIVE
To look for associations between distinct genetic polymorphisms and clinical subgroups of the disease.


METHODS
A total of 210 patients and 343 healthy control subjects, all adult, unrelated, white, Spanish individuals.


METHODS
DNA was purified from peripheral blood samples and was typed by sequence-specific oligonucleotide polymerase chain reaction (PCR) method for human leukocyte antigen (HLA)-DRB1 alleles (IBD3) and by allele-specific PCR for NOD2/CARD15 (IBD1) polymorphisms.


RESULTS
NOD2/CARD15 mutations and HLA-DRB1*07 confer susceptibility only to the ileal location of the disease, whereas HLA-DRB1*0103 is associated only with the colonic location of the disease. The IBD3 effect was overshadowed by IBD1 mutations when present.


CONCLUSIONS
The studied genetic polymorphisms of Crohn's disease basically determine the location of the disease and, only secondarily, the clinical form of the disease. This appears to be true for both inflammatory bowel diseases as HLA-DRB1*0103 is associated both with colonic Crohn's disease and ulcerative colitis.
Fernandez
Laura
L
Department of Clinical Immunology, Hospital Clinico San Carlos, Madrid, Spain.
Mendoza
Juan L
JL
Martinez
Alfonso
A
Urcelay
Elena
E
Fernandez-Arquero
Miguel
M
Garcia-Paredes
Julio
J
Peña
A Salvador
AS
Diaz-Rubio
Manuel
M
de la Concha
Emilio G
EG
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003424:Crohn Disease / Q000235:genetics*; D004247:DNA / Q000032:analysis / Q000097:blood; D005260:Female; D020022:Genetic Predisposition to Disease; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006801:Humans; D007223:Infant; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D008297:Male; D053473:Nod2 Signaling Adaptor Protein; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D013030:Spain; D044465:White People / Q000235:genetics
D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D047908:Intracellular Signaling Peptides and Proteins; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D004247:DNA