Primary immunodeficiencies are disorders in which part of the body's immune system is missing or does not function properly. When a defect in the immune system is inherited (carried through the genes), it is called primary, or inherited, immune deficiency. There are over 350 forms of Primary Immunodeficiency (PI), ranging widely in severity. PI often presents itself in the form of "ordinary" infections.
Physicians sometimes treat the infections while missing the underlying cause, allowing the illnesses to recur, and leaving the patient vulnerable to vital organ damage, physical disability, and even death.
For more information about PI, see the sections below.