Severe Combined Immunodeficiency (SCID) is the result of several defective genes in a child's immune system. Kids with SCID are extremely susceptible to life-threatening infections. SCID is sometimes known as the "bubble boy disease" because of the 1976 television movie about David Vetter, the boy who spent his childhood in a plastic bubble. Despite the extreme precautions to keep him safe from pathogens, David died after an unsuccessful bone marrow transplant when he was 12.
Severe combined immunodeficiency is quite rare. Researchers estimate only between 40-100 babies are born with SCID in the United States annually. The numbers may be higher, though, because there likely are infants who die from infections before they were diagnosed with SCID.
There are two main types of SCID.
Symptoms of SCID are both recurrent and severe.
If your baby shows any of the following symptoms in his first year of life, see a doctor:
Severe combined immunodeficiency (SCID) is a rare genetic disorder that affects the immune system. SCID leads to deadly infections in infants. Without treatment, babies with SCID usually die before their 2nd birthday. Because the more common form of the disease, XSCID, affects only males, boys are more likely than girls to have the disorder.
Because SCID is both rare and inherited, it is hard to detect in children. There are fewer than 100 known cases of SCID each year in the United States, but some babies likely die from infections without ever being diagnosed with the condition. To make diagnosis even more difficult, most babies born with SCID are asymptomatic at birth due to protection from their mother’s antibodies. If your infant suffers from frequent viral, fungal or bacterial infections in the first year of life, see a doctor.
According to the American Association for Clinical Chemistry (AACC), identifying SCID in newborns is a pediatric emergency. SCID runs in families, so it is important to let your doctor know if you've had a child die from a severe infection in the past. New life-saving treatments make newborn screening for SCID more important than ever. Screening for SCID includes DNA sequencing - if there is a family history of immunodeficiency disease, doctors can perform this test to see if your child has it. Blood tests also will be performed to count T and B cells and determine their level of functioning, which also can indicate SCID in infants.
Diagnosing SCID before your child gets an infection could save his life. Without treatment, there is a 100 percent morbidity rate for children with the disease.
While prenatal screening is becoming more common for a child with Severe Combined Immunodeficiency, it is still rarely diagnosed in newborns. Most infants with SCID aren't diagnosed until they are just over 6 months of age. Diagnosis usually follows several infections, or a child's failure to thrive.
If diagnosed early, up to 80 percent of infants with SCID who receive stem cell treatment will survive. Left untreated, most children with the disease will perish by the time they are 2-years old.
SCID is an inherited mutation of genes in the immune system. It is also called the “bubble boy” disease due to the popularity of the 1976 movie starring John Travolta.
Only 40 to 100 known cases of SCID are diagnosed in the U.S. each year. The disease may be more common, but most children with it die from severe infections before they turn 2.
Due to the genetic mutation, children with the type known as XSCID don’t produce enough disease-fighting B and T white blood cells; this is linked to the X chromosome. Kids with another form, called ADA SCID, don’t produce the enzyme adenosine deaminase, which compromises their immune system.
Children with SCID are susceptible to frequent infections that may be unresponsive to treatment. Symptoms include recurrent, severe viral, fungal or bacterial infections and pneumonia.
Most SCIDs are detected with DNA screening in newborns. Blood tests can also determine whether a child has enough B and T cells to fight infections.
The most effective treatment for SCID is a stem cell transplant from a healthy donor. Other treatments involve isolating children to prevent infections, and enzyme replacement therapy.
Babies who receive a successful stem cell transplant have an 80 percent chance of living a normal, healthy life. Without treatment, infants with SCID will not survive into childhood.