Skip to content
knowrare
HealthSignal
Your condition community

Living with Severe combined immunodeficiency disease

A group of inherited immune conditions in which T cells and B cells do not work properly, causing repeated infections.

Understanding Severe combined immunodeficiency disease

Severe combined immunodeficiency (SCID) is a group of inherited immune system disorders affecting both T cells and B cells.

Common signs include repeated infections, such as ear infections, pneumonia, bronchitis, oral thrush, and diarrhea. Because of repeated infections, children do not grow and gain weight as expected. It can be caused by changes in any of several genes. The most common type is X-linked SCID, and another is caused by adenosine deaminase (ADA) deficiency.

Signs & symptoms

GARD doesn't list a symptom list for this condition. Its summary describes these:

  • Repeated infections
  • Ear infections
  • Pneumonia or bronchitis
  • Oral thrush
  • Diarrhea
  • Poor growth and weight gain

Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.

Diagnosis

  1. Talk with your doctor

    Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.

  2. See a specialist

    Specialists who may be involved include allergy and immune system specialists and genetic specialists.

  3. Ask which tests can help

    Your care team will decide which exams and tests can confirm the diagnosis.

  4. Connect with expert centers

    Immune Deficiency Foundation may keep lists of experts for this condition.

Care & treatment

Care team
Allergy and immune system specialists (allergists / immunologists); Genetic specialists (geneticists)
Expert care
Expert lists: Immune Deficiency Foundation
Treatment
GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
Research
Clinical trials and observational studies may be options. See the research section below.

General information, not medical advice. Your care team makes the decisions.

Everyday life

Living with a rare condition is easier with support.

  • Connect with Jeffrey Modell Foundation and other patient organizations
  • Keep notes on symptoms, changes and questions for appointments
  • Ask about patient registries that help research
  • Look into financial aid and travel resources for care visits
Bring these questions to your next doctor visit
Which type of SCID is it, and which gene is involved?
What treatment options are available?
How can we lower the chance of infections?

Quick facts

Symptoms usually startNewborn and as an Infant
InheritanceAutosomal Recessive, X-Linked

It can be caused by changes in any of several genes. It is inherited in an X-linked recessive way most commonly, or an autosomal recessive way.

Genetic

Also known as: combined t and b cell inborn immunodeficiency; combined t-cell and b-cell immunodeficiency; immunodeficiency, severe combined; scid; scid - severe combined immunodeficiency; severe combined immune deficiency

Patient organizations

Source: NIH GARD · Severe combined immunodeficiency diseaseGARD ID 7628 · GARD page updated September 2026 · Plain-language summary by Know Rare; editorial review pending. General information, not medical advice.

You are more than your diagnosis

Perspectives from people navigating life with Severe combined immunodeficiency disease.

Explore the Severe combined immunodeficiency disease blog

Explore research for Severe combined immunodeficiency disease

Explore actively recruiting Severe combined immunodeficiency disease studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Severe combined immunodeficiency disease with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
  • Share your city to look for research near you
  • Eligibility is confirmed by the study team

Powered by HealthSpark, our AI chat helper

I can help you find recruiting Severe combined immunodeficiency disease studies. Enter a ZIP code, address or city below and I'll look within 50 miles.

Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.

Get Signals for Severe combined immunodeficiency disease

Stay in the loop with community stories and updates from medical researchers.

HealthStoryfor Severe combined immunodeficiency disease

Create a living journal that talks back

HealthStory evolves private journaling with a living AI journal that talks back and asks thoughtful questions, helping you capture your Severe combined immunodeficiency disease experiences more deeply and prepare for better conversations with your doctors and care team.

Start your journal

Your journal is private. Sharing your story publicly is a separate choice, made with Share your story above.