St. Jude Family of Websites
Explore our cutting edge research, world-class patient care, career opportunities and more.
St. Jude Children's Research Hospital Home
Also called: bubble boy disease, bubble baby disease
Severe combined immunodeficiency (SCID) is a rare disorder of the immune system. It is a genetic condition that is passed down from parent to child. Children born with SCID have defects in their immune system cells. These children have problems fighting infections.
The immune system has 3 types of white blood cells: T cells, B cells, and NK cells. These cells protect the body from viruses, bacteria, and other infections. Both T and NK cells find and attack infections. The B cells make antibodies that protect against infections.
In SCID, T cells, B cells, and NK cells are missing or do not work properly. Children with SCID get infections easily because they do not have a working immune system.
SCID occurs in about 1 in every 50,000 babies born. About 70 infants are found to have SCID in the United States each year.
Symptoms of SCID may include:
Ear infections
Lung problems such as pneumonia or bronchitis
Oral thrush (a type of yeast that creates white, sore areas in the mouth)
Diarrhea
Failure to grow and gain weight as expected
SCID is caused by a change (mutation) in 1 or more genes that are involved in the immune system.
The most common type of SCID is X-linked severe combined immunodeficiency disease (SCID-Xl). It usually occurs in boys because the mutated gene is on the X chromosome.
SCID is a genetic condition. When a child has SCID, parents should talk to a genetic counselor about the chances of future children having the same condition.
Screening is the most common way to find out if a child has SCID. Newborn infants are screened for SCID at birth. For children who have not been screened, blood tests can be done to confirm SCID.
The most effective treatment for SCID is bone marrow transplant (also known as a stem cell transplant). In this treatment, a child with SCID receives healthy stem cells from a matched donor. This donor is usually a healthy brother or sister.
The new cells rebuild the immune system of the child with SCID. It is possible for children who receive this type of transplant to be cured. Unfortunately, less than 1 in 4 children with SCID have a matched donor.
Without a matched donor, doctors may use stem cells from an unrelated donor or parent. Children who receive these cells do not do as well as those with fully matched donors. About 1 in 3 people treated with a transplant from partially matched donors will develop immune system problem years later.
A bone marrow transplant has the best chance of working when it occurs in the first few months of a child’s life. That is why an early SCID diagnosis is important.
Research at St. Jude offers better treatment options for children with X-linked severe combined immunodeficiency disease (SCID-Xl). The St. Jude research study called LVXSCID-ND treats SCID-X1 with a new method called gene therapy. In this process, bone marrow stem cells are removed from the child. A corrected (normal) copy of the abnormal gene is added to those bone marrow stem cells. These cells are then transplanted into the child’s body.
Without treatment, children with SCID usually die from infections within the first 2 years of life. Early bone marrow transplant, frequent follow-ups, and prompt treatment for infections increase survival rate.
St. Jude offers clinical trials and research studies for children, teens, and young adults with SCID. Learn more about clinical research at St. Jude.
There are no open clinical trials for severe combined immunodeficiency (SCID) at this time.
Browse open clinical trialsPatients accepted to St. Jude must have a disease we treat and must be referred by a physician or other qualified medical professional. We accept most patients based on their ability to enroll in an open clinical trial.
Call: 1-888-226-4343 (toll-free) or 901-595-4055 (local) | Fax: 901-595-4011 | Email: referralinfo@stjude.org | 24-hour pager: 1-800-349-4334