Seronegative celiac disease (SNCD) is defined by the negativity of anti-tissue transglutaminase antibodies in the presence of a positive histology on duodenal biopsy samples, i.e. inflammatory infiltrate of intra-epithelial lymphocytes (IELs > 25/100 enterocytes), mild villous atrophy and uneven brush border associated to human leukocyte antigen (HLA) haplotype DQ2 and/or DQ8. Here, TGM2 is linked to celiac disease.