The answer is the Severe combined immunodeficiency (SCID).
Explanation:
SCID which is an immune deficiency that is present at birth, is deadly without treatment. Children born with SCID are in constant danger of infections from bacteria, viruses, and fungi. This is because of lack of some essential white blood cells.
The disease however can be essentially cured by a bone-marrow transplant from a related donor, for example, a sibling that is a match in terms of certain immune system proteins.
