Severe combined immunodeficiency, SCID, also known as alymphocytosis, Glanzmann–Riniker syndrome, severe mixed immunodeficiency syndrome, and thymic alymphoplasia, is a genetic disorder characterized by the disturbed development of functional T cells and B cells caused by numerous genetic mutations that result in heterogeneous clinical presentations. SCID involves defective antibody response due to either direct involvement with B lymphocytes or through improper B lymphocyte activation due to non-functional T-helper cells. Consequently, both “arms” (B cells and T cells) of the adaptive immune system are impaired due to a defect in one of several possible genes. SCID is the most severe form of primary immunodeficiencies, and there are now at least nine different known genes in which mutations lead to a form of SCID. It is also known as the bubble baby disease and bubble boy disease because its victims are extremely vulnerable to infectious diseases and some of them, such as David Vetter, have become famous for living in a sterile environment. SCID is the result of an immune system so highly compromised that it is considered almost absent.
SCID patients are usually affected by severe bacterial, viral, or fungal infections early in life and often present with interstitial lung disease, chronic diarrhea, and failure to thrive. Ear infections, recurrent Pneumocystis jirovecii (previously carinii) pneumonia, and profuse oral candidiasis commonly occur. These babies, if untreated, usually die within 1 year due to severe, recurrent infections unless they have undergone successful hematopoietic stem cell transplantation
Severe Combined Immune Deficiency (SCID), also known as the bubble boy disease, is a rare, serious disorder where a child lacks the ability to fight off infections. Babies with SCID are placed in isolation both before and after the corrective treatment to protect them or isolate them from germs that could make them sick. Riley’s parents share their perspective on her diagnosis, treatment, and isolation. Her story of survival is one of many. Fortunately, many children with SCID are now grown, living healthy, productive lives. SCID can affect any infant, regardless of gender, race, ethnicity or socioeconomic status. Without appropriate early treatment, including the critical period of isolation, these babies cannot survive. Therefore it is essential that newborn screening for SCID is established in all 50 states because all babies, no matter where they are born, deserve a healthy life.