Mutations in genes that affect the development or function of T and B cells [DCLRE1C(ARTEMIS), ZAP70, RAG1/2, IL2RG, ILRA7, LIG4, JAK3, ADA] can result in intestinal inflammation along with recurrent infections from severe combined immunodeficiency (SCID) (30–32). The gene discussed is ADA; the disease is severe combined immunodeficiency.