A survey of 10,000 American households revealed that the prevalence of diagnosed<unk>  approaches 1 in 1200. This figure does not take into account people with mild immune system defects who have not received a formal diagnosis. Milder forms of<unk> , such as selective immunoglobulin A deficiency, are fairly common, with random groups of people (such as otherwise healthy blood donors) having a rate of 1:600. Other disorders are distinctly more uncommon, with incidences between 1:100,000 and 1:2,000,000 being reported.
Primary immunodeficiency
Combined immunodeficiencies
Severe combined immunodeficiency
Selective immunoglobulin A deficiency
Common variable immunodeficiency
IgG deficiency
X-linked agammaglobulinemia
Adult-onset immunodeficiency syndrome