Severe Combined Immunodeficiency

**Definition:** Group of rare congenital disorders characterized by impairment of both humoral and cell-mediated immunity, leukopenia, and low or absent antibody levels. It is inherited as an X-linked or autosomal recessive defect. Mutations occurring in many different genes cause human Severe Combined Immunodeficiency (SCID).

**Tree numbers:** - C16.320.798.750 - C16.614.815 - C18.452.284.800 - C20.673.795.750

**Synonyms:** - Immunodeficiency Syndrome, Severe Combined - Severe Combined Immunodeficiency Syndrome - Severe Combined Immune Deficiency - Immunologic Deficiency, Severe Combined - Severe Combined Immunologic Deficiency - Immunodeficiency, Severe Combined