The present investigation aims to study the prevalence rate and clinical characteristics of CD among Saudi children with T1D using a combination of the most sensitive and specific screening serologic tests (anti- tissue transglutaminase antibodies IgA [anti-TTG] and ednomyseal antibodies [EMA]) and to determine the lower cut-off value of anti- anti-TTG level that best predicts CD in children with T1D. This evidence concerns the gene CD79A and type 1 diabetes mellitus.