Severe Combined Immunodeficiency (SCID)

Newborn Screening for Severe Combined Immunodeficiency

Severe Combined Immunodeficiency (SCID) is the name for a group of inherited disorders that cause babies to be born without a working immune system. These disorders are also called primary immune deficiency disorders (PID). SCID is also sometimes called:

• Severe combined immune deficiency
• Severe mixed immunodeficiency syndrome
• Primary immune deficiency
• Bubble boy disease

Newborns with SCID may seem healthy at first because their mother's immune system protects them from infections for the first few weeks of life. However, without necessary treatment, common infections and vaccines can be life threatening to these infants. The immune system functions with the help of lymphocytes. Lymphocytes are a type of white blood cell made by the bone marrow. There are two types of lymphocytes: T cells and B cells. People with SCID have a severe defect in their T cells, and B cells that do not work well. People with SCID are not able to fight off common infections. They also cannot make antibodies to protect themselves.