Severe Combined Immunodeficiency

What is severe combined immunodeficiency?

Severe Combined Immunodeficiency (SCID) is a rare but very serious condition where a baby is born with almost no immune system. It is sometimes called "bubble baby disease" because these infants have no natural protection against germs. In a baby with SCID, the body fails to make the specialised "soldier" cells (called T-cells) needed to fight off even minor illnesses like a cold or a diaper rash. Because the baby is still protected by their mother’s antibodies for the first few weeks of life, they usually look perfectly healthy at birth, making the condition impossible to see without a specific test.

Why do we need screening for severe combined immunodeficiency?

We need this screening, which is done as part of the routine newborn blood spot (heel prick) test, because for these babies, a common germ can quickly become life-threatening. If SCID is caught within the first few weeks of life, before the baby catches a major infection, it can often be cured with a bone marrow transplant or gene therapy. However, if the condition isn't found until after the baby becomes very sick, these treatments are much harder on the body and less likely to work. Screening ensures these babies can get the help they need immediately, giving them the chance to build a healthy, working immune system.