Analysis of single nucleotide polymorphisms in the region of CLDN2-MORC4 in relation to inflammatory bowel disease.
OBJECTIVE
To investigate a possible genetic influence of claudin (CLDN)1, CLDN2 and CLDN4 in the etiology of inflammatory bowel disease.


METHODS
Allelic association between genetic regions of CLDN1, CLDN2 or CLDN4 and patients with inflammatory bowel disease, Crohn's disease (CD) or ulcerative colitis were investigated using both a case-control study approach (one case randomly selected from each of 191 Swedish inflammatory bowel disease families and 333 controls) and a family-based study (463 non-Swedish European inflammatory bowel disease -families). A nonsynonymous coding single nucleotide polymorphism in MORC4, located on the same linkage block as CLDN2, was investigated for association, as were two novel CLDN2 single nucleotide polymorphism markers, identified by resequencing.


RESULTS
A single nucleotide polymorphism marker (rs12014762) located in the genetic region of CLDN2 was significantly associated to CD (case-control allelic OR = 1.98, 95%CI: 1.17-3.35, P = 0.007). MORC4 was present on the same linkage block as this CD marker. Using the case-control approach, a significant association (case control allelic OR = 1.61, 95%CI: 1.08-2.41, P = 0.018) was found between CD and a nonsynonymous coding single nucleotide polymorphism (rs6622126) in MORC4. The association between the CLDN2 marker and CD was not replicated in the family-based study. Ulcerative colitis was not associated to any of the single nucleotide polymorphism markers.


CONCLUSIONS
These findings suggest that a variant of the CLDN2-MORC4 region predisposes to CD in a Swedish population.
Division of Medical Diagnostics, Ryhov County Hospital, 55185 Jönköping, Sweden.
Jan
J
Söderman
Elisabeth
E
Norén
Malin
M
Christiansson
Hanna
H
Bragde
Raphaele
R
Thiébaut
Jean-Pierre
JP
Hugot
Curt
C
Tysk
Colm A
CA
O'Morain
Miquel
M
Gassull
Yigael
Y
Finkel
Jean-Frédéric
JF
Colombel
Marc
M
Lémann
Sven
S
Almer
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D062445:Claudin-1 / Q000235:genetics; D057167:Claudins / Q000235:genetics*; D003093:Colitis, Ulcerative / Q000235:genetics*; D003424:Crohn Disease / Q000235:genetics*; D005060:Europe; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000235:genetics*; D016017:Odds Ratio; D010375:Pedigree; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
C568108:CLDN1 protein, human; C491875:CLDN2 protein, human; D062445:Claudin-1; D057167:Claudins; C523050:MORC4 protein, human; D009687:Nuclear Proteins
Crohn’s disease; Genetic predisposition; Inflammatory bowel disease; Single nucleotide polymorphism; Tight junctions