Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose: Genome-wide association studies (GWAS) have successfully identified common variants that contribute to Behçet’s disease (BD) susceptibility. However, associations due to rare and low-frequency variants have not been evaluated. It has long been debated whether the innate immune system is involved in the pathogenesis of BD. Clinical manifestations such as episodic inflammation and neutrophil recruitment to the sites of inflammation strongly suggest that the innate immune response plays an important role, although genetic evidence to support this hypothesis is sparse. Recent advances in sequencing technology allow investigators to re-sequence targeted genes to discover novel variants in large collections of cases with complex genetic traits and genetically matched controls.
Methods: We performed deep re-sequencing of two GWAS-identified genes (IL23R and IL10) and eleven genes known to have roles in innate immunity (IL1B, IL1R1, IL1RN, NLRP3, MEFV, TNFRSF1A, PSTPIP1, CASP1, PYCARD, NOD2, and TLR4) in 382 cases and 384 controls in Japanese population and 384 cases and 384 controls in Turkish population. Non-synonymous variants identified by deep exonic re-sequencing were validated by individual genotyping of 4955 samples. For statistical analyses, we performed C-alpha test, adaptive sum test and step-up methods to identify the roles of rare and low-frequency variants associated with BD.
Results: We found a non-random distribution of rare and low-frequency variants in cases and controls implicating IL23R, MEFV, TLR4, and NOD2 in BD susceptibility. Adaptive sum test and step-up methods corroborated the results for IL23R in both populations and for TLR4 in the Turkish population. Carriage of MEFV-M694V, known to cause recessively inherited familial Mediterranean fever, conferred BD risk in Turkish samples (Cochran-Mantel-Haenszel meta analysis p=1.79×10-12).
Conclusion: These findings implicate innate immune and bacterial sensing mechanisms in BD pathogenesis. We are currently extending our re-sequencing efforts to CCR1, KLRK1, KLRC1-4, STAT4, and ERAP1, common variants of which we recently identified by GWAS.
Disclosure:
Y. Kirino,
None;
Q. Zhou,
None;
Y. Ishigatsubo,
None;
N. Mizuki,
None;
I. Tugal-Tutkun,
None;
E. Seyahi,
None;
Y. Ozyazgan,
None;
F. S. Sacli,
None;
B. Erer,
None;
Z. Emrence,
None;
A. Cakar,
None;
D. Ustek,
None;
A. Meguro,
None;
A. Ueda,
None;
M. Takeno,
None;
M. J. Ombrello,
None;
C. Satorius,
None;
B. Maskeri,
None;
J. Mullikin,
None;
H. W. Sun,
None;
G. Gutierrez-Cruz,
None;
Y. Kim,
None;
A. Gül,
None;
D. L. Kastner,
National Institutes of Health,
7;
E. F. Remmers,
None.
« Back to 2012 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/targeted-deep-re-sequencing-implicates-rare-and-low-frequency-coding-variants-in-il23r-mefv-tlr4-and-nod2-in-behcets-disease/