TGM2 and cranioectodermal dysplasia: In contrast to classic CeD, those with seronegative disease have negative transglutaminase (TTG), deamidated gliadin peptide (DGP), and anti-endomysial antibody (EMA) IgA and IgG, while still having HLA testing compatible with development of CeD, villous atrophy on duodenal biopsy, as well as clinical and histologic response to a gluten-free diet [3].