Folate-responsive immunodeficiency-114 (IMD114) is an autosomal recessive immunologic disorder characterized by the onset of oral ulcers and recurrent skin and respiratory infections in early infancy. Affected individuals have lip fissures, skin sores and abscesses, genital dermatitis, chronic diarrhea, and poor overall growth. Laboratory studies show megaloblastic anemia, thrombocytopenia, and lymphopenia with decreased Ig levels. Some individuals have global developmental delay, often with brain imaging abnormalities. Treatment with folic acid supplementation results in significant clinical improvement of the hematologic and immunologic abnormalities, although neurologic abnormalities, if already present, do not respond to treatment. Early intervention and treatment with folic acid supplementation may prevent or delay neurologic deficits in affected infants (Gok et al., 2023; Shiraishi et al., 2023).