The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guidelines from 2012 recommend testing for the tTG-IgA, which is highly sensitive and specific as the initial screening test for diagnosing suspected celiac disease, and the total IgA to rule out selective IgA deficiency. The gene discussed is TGM2; the disease is selective IgA deficiency disease.