Severe Combined Immunodeficiency

What is severe combined immunodeficiency?

Severe combined immunodeficiency (SCID) is very rare, genetic disorder, affecting between 50 and 100 children born in the U.S. every year. SCID is often called “bubble boy disease,” made known by the 1976 movie “The Boy in the Plastic Bubble.” 

Essentially, children with SCID lack the ability to produce an immune system. The human immune system constantly patrols, protects and defends the body from all types of “enemies,” including:

  • bacteria
  • viruses
  • parasites
  • fungi

The immune system first takes root in a developing fetus’s bone marrow. That’s where some stem cells eventually mature into the two cell types that play the biggest role in warding off infection: T cells (white blood cells that identify and attack perceived “invaders”) and B cells (white blood cells that produce antibodies against infection).

A child with SCID:

  • can't produce T cells
  • doesn't have working B cells (because there are no T cells for them to work with)
  • has virtually no immune system

Without a functioning immune system, a child with SCID has no way of warding off infections. He or she will be at constant risk for:

  • pneumonia
  • chronic diarrhea
  • thrush infections of the mouth and skin
  • many other types of infection, including severe viral infections and invasive bacterial or fungal infections

How we care for severe combined immunodeficiency

Boston Children’s Hospital has a long history of caring for children with complex disorders of the immune system. Clinicians in our Division of Allergy and Immunology are international leaders in understanding and treating rare conditions like SCID.

Most children with SCID receive a stem cell transplant (also known as a bone marrow transplant), so that they can develop new white blood cells, replenishing their immune systems. The Dana-Farber/Boston Children's Stem Cell Transplant Center — one of the first pediatric transplant centers in the nation — has a state-of-the-art stem cell transplant facility designed specifically for children and teens undergoing stem cell transplant — minimizing their exposure to harmful toxins.

Gene Therapy for SCID

Boston Children's is helping to lead an international gene therapy trial for SCID. The trial — which transplants genetically modified stem cells from a child’s own bone marrow — may signify a promising new approach to fighting and defeating the disease. Learn more about our Gene Therapy Program.