"Adding DNA-test for Screening of HLA-DQ2 and DQ8 to Improve Early Diagnosis of Celiac Disease"

Phase 1 and 2: After blood collection (in combination with regular care) and informed consent, a blood droplet obtained by an additional fingerprick (Phase 1 and just an extra droplet from an existing finger prick for Phase 2) will be deposited on filter paper S\&S 903™ (Schleicher and Schuell). DNA will be isolated using the QIAamp method designated for this purpose from dried blood spots (Qiagen). The results of the HLA-DQ2 and DQ8-typing using the dried blood spots will be compared with the results of the traditional HLA-typing. Factors that may influence the quality of the material will be taken into account in the validation process.