<h4>Context</h4>Anti-transglutaminase antibodies (anti-TTG IgA) titer is associated with mucosal damage in celiac disease (CD).<h4>Objective</h4>The primary focus was to correlate anti-TTG IgA titer, HbA1c when CD occurs (HbA1cCD), and Marsh grade in children and adolescents with type 1 diabetes (T1D) at the time of CD diagnosis. This evidence concerns the gene CD79A and Cowden disease.