ATG16L1 and IL23 receptor (IL23R) genes are associated with disease susceptibility in Hungarian CD patients.
BACKGROUND
North American and European genome-wide association scans have identified ATG16L1 and IL23R as novel inflammatory bowel disease (IBD) susceptibility genes and subsequent reports confirmed these findings in large independent populations. The aims of this study were to investigate the association and examine genotype-phenotype relationships in a Hungarian IBD cohort.


METHODS
415 unrelated IBD patients (CD: 266, age: 35.2+/-12.1 years, duration: 8.7+/-7.5 years and UC: 149, age: 44.4+/-15.4 years, duration: 10.7+/-8.9 years) and 149 healthy subjects were investigated. IL23R Arg381Gln (R381Q, rs11209026) and ATG16L1 Thr300Ala (T300A, rs2241880) polymorphisms were tested using LightCycler allele discrimination method. Detailed clinical phenotypes were determined by reviewing the medical charts.


RESULTS
The association between IL23R rs11209026, ATG16L1 rs2241880 and CD was confirmed (OR(IL23R381Q): 0.38, 95% CI: 0.16-0.87; OR(ATG16L1300AA): 1.86, 95% CI: 1.04-3.40). No difference was found between patients with UC and either controls or CD. In CD, IL23R 381Gln heterozygosity was associated with inflammatory disease (70% vs. 34%, p=0.037), while disease restricted to the colon was more prevalent in patients with the ATG16L1 300Ala/Ala homozygosity (33.3% vs. 21.1%, p=0.036). In addition, carriage of the variant alleles did not predict response to steroids, infliximab or need for surgery.


CONCLUSIONS
We confirmed that ATG16L1 and IL23R are susceptibility loci for CD in Hungarian CD patients. Further studies are needed to confirm the reported phenotype-genotype associations found in this study.
Lakatos
P L
PL
1st Department of Medicine, Semmelweis University, Budapest, Hungary. kislakpet@bel1.sote.hu
Szamosi
T
T
Szilvasi
A
A
Molnar
E
E
Lakatos
L
L
Kovacs
A
A
Molnar
T
T
Altorjay
I
I
Papp
M
M
Tulassay
Z
Z
Miheller
P
P
Papp
J
J
Tordai
A
A
Andrikovics
H
H
D000328:Adult; D017677:Age Distribution; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins / Q000235:genetics*; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D016001:Confidence Intervals; D003424:Crohn Disease / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D005838:Genotype; D006801:Humans; D006814:Hungary / Q000453:epidemiology; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000208:ethnology / Q000235:genetics; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D018123:Receptors, Interleukin / Q000235:genetics*; D018570:Risk Assessment; D017678:Sex Distribution; D044465:White People / Q000706:statistics & numerical data
C518959:ATG16L1 protein, human; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; C515500:IL23R protein, human; D018123:Receptors, Interleukin