congenital sideroblastic anemia-B-cell immunodeficiency-periodic fever-developmental delay syndrome (Monarch Disease Ontology identifier MONDO_0014487) is congenital sideroblastic anemia -B cell immunodeficiency- periodic fever-developmental delay syndrome is a form of constitutional sideroblastic anemia, characterized by severe microcytic anemia, B-cell lymphopenia, panhypogammaglobulinemia and variable neurodegeneration. The disease presents in infancy with recurrent febrile illnesses, gastrointestinal disturbances, developmental delay, seizures, ataxia and sensorineural deafness. Most patients require regular blood transfusion, iron chelation, and intravenous immunoglobulin (IVIG) replacement. Stem cell transplantation has been reported to be successful. Also known as: SIFD, SIFD syndrome.