UCSF Benioff Children’s Hospital

Severe combined immunodeficiency disease (SCID) represents a group of diseases with many different causes but, in general, results in children who have severe defects in the function of their lymphocytes. These deficiencies result in a significant reduction or absence of function of T and B cells (called lymphocytes) that is essential for fighting bacterial, viral and certain fungal infections.

Children with SCID usually become sick from infections, skin rashes and failure to gain weight within the first three to six months of life and without critical care and a transplant often die prior to 1 year of age.