A rare inherited condition found only in males, in which there is no GAMMA-GLOBULIN in the blood. Present from birth, it causes particular susceptibility to infections, as ANTIBODIES cannot be made to fight any infecting micro-organism. Acquired agammaglobulinaemia is a rare disorder occurring in both sexes in their 20s and 40s, characterised by recurrent bacterial infections. The cause is a disturbance in the working of the immune system. (See IMMUNITY.)