Background and Aims: The first genome-wide association study on celiac disease and its follow-up have identified eight new loci that contribute significantly towards celiac disease risk. Seven of these contain genes controlling adaptive immune responses, including IL2/IL21 (4q27), RGS1 (1q31), IL18RAP (2q11-2q12), CCR3 (3p21), IL12A (3q25-3q26), TAGAP (6q25) and SH2B3 (12q24).
Methods: We selected the nine most associated single nucleotide polymorphisms to tag the eight new loci in an Italian cohort composed of 538 celiac disease patients and 593 healthy controls.
Results: Common variation in IL2/IL21, RGS1, IL12A/SCHIP and SH2B3 was associated with susceptibility to celiac disease in our Italian cohort. The LPP and TAGAP regions also showed moderate association, whereas there was no association with CCR3 and IL18RAP.
Conclusion: This is the first replication study of six of the eight new celiac disease loci; it is also the first celiac disease association study in a southern European cohort. Our results may imply there is a genuine population difference across Europe regarding the loci contributing to celiac disease.