Most children born with immune deficiencies die at an early age and nearly all succumb in young adulthood.
The standard treatment for certain congenital abnormalities of the immune system is a bone marrow transplant. The donor must be an exact match for the patient or rejection occurs (host versus graft disease). Some children born in the late 1990s with defective immune systems have seemingly been cured by umbilical cord blood transplants from unrelated donors.