a congenital disease affecting T cells that can result from a mutation in any one of several different genes; children with it are susceptible to infectious disease; if untreated it is lethal within the first year or two of life

Also called SCID. A rare congenital disorder of the immune system characterized by the inability to produce a normal complement of antibodies and T-cells.

defect resulting in loss of B- and T-cell activity

A genetic disorder in which afþicted individuals have no functional immune system and are prone to infections. Both the cell-mediated immune response and the antibody-mediated response are absent.

a condition, often genetic, in which more than one component of the immune system is compromised or dysfunctional, leaving an individual prone to a range of opportunistic illnesses and cancers.

disease This describes the condition where a child is born without most defences of the immune system. The child often needs to be isolated or live in a "bubble" environment.

An immunodeficiency disease in which the immune system mounts neither T-cell mediated nor humoral responses. Fatal if untreated. Usually results from T cell deficiencies (Janeway et al., 2005).

Severe combined immunodeficiency, or SCID, is a genetic disorder in which both "arms" (B cells and T cells) of the adaptive immune system are crippled, due to a defect in one of several possible genes. SCID is a severe form of heritable immunodeficiency. It is also known as the "bubble boy" disease because its victims are extremely vulnerable to infectious diseases.