FOXP3 and immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome: Importantly, four patients had dual diagnoses with glucose-6-phosphate dehydrogenase (G6PD) deficiency: X-linked SCID (IL2RG), C6 deficiency (C6), IPEX syndrome (FOXP3), DiGeorge syndrome (TBX1).