Cases mentioned in the literature described patients with mutations in different domains of FOXP3; A child from Serbia with IVS7 + 5G>A mutations in the FOXP3 gene presented by the end of his first month by type 1 diabetes and chronic diarrhea followed by dehydration and disordered development, later he had facial eczema and laboratory thyroiditis (6). The gene discussed is FOXP3; the disease is type 1 diabetes mellitus.