Other important findings included that IgA EmA positivity was never found in cases without IgA anti-TG2 [22]; about two thirds of the IgA TG2/EmA negative cases had IgA deficiency (and tested positive for IgG anti-TG2/DGP) [17] and, finally, that seronegative CD was identified only in a small subset of patients (1.4%) [23]. This evidence concerns the gene TGM2 and selective IgA deficiency disease.