Extensive celiac disease (ECD), characterized by involvement of the second portion of the duodenum, was associated with a significantly increased prevalence of short stature (p < 0.001) and iron deficiency anemia (p = 0.010), as well as substantially higher titers of tTG antibodies (p < 0.001). The gene discussed is TGM2; the disease is familial atrioventricular septal defect.