Adult-onset immunodeficiency with anti-interferon-gamma autoantibodies is an immunodeficiency disorder. It is associated with susceptibility to disseminated infections (dispersed throughout the body) caused by organisms that typically affect only people with weak immune systems (opportunistic pathogens). People with this disorder produce higher amounts of anti-interferon-gamma autoantibodies. These are specific immune system proteins that mistakenly target a person's own tissues. It is predominantly reported in Southeast Asians who were previously healthy. Pathogens that cause infections in people with this disorder may include non-tuberculous mycobacteria, non-typhoidal salmonella, cytomegalovirus, Penicillium marneffei, and varicella zoster virus. Symptoms depend on the infection(s) present in each person. The cause of developing anti-interferon-gamma autoantibodies is unclear, but genetic factors are suspected to be involved. Studies have suggested an association with certain HLA genes. These genes help the immune system distinguish between the body's own proteins and those made by foreign invaders. Some have suggested that an infection may initially trigger the production of autoantibodies, and repeated infections lead to their increased activity.