Inherited immune disorders · Diagnosis guide
Severe combined immunodeficiency (SCID)
SCID is a group of genetic conditions that profoundly impair T-cell immunity. Other immune cells may also be affected, depending on the subtype. Newborn screening can identify a child before symptoms develop. Suspected SCID needs urgent specialist assessment and infection prevention directed by the care team. Donor transplantation is an established treatment for many forms; selected subtypes also have gene-therapy or enzyme-replacement options. The exact genetic cause matters. RAG1 and RAG2 variants, for example, can also cause less severe or later-onset immune disorders; not every variant causes classic SCID.
Explore the subtypes
The exact diagnosis helps explain the options. Your care team can clarify the name on your report.
- Condition guide
Adenosine deaminase-deficient severe combined immunodeficiency
ADA-deficient SCID is a genetic immune disorder in which a missing enzyme allows toxic metabolites to build up, impairing infection-fighting cells. ADA deficiency can also affect organs outside the immune system and can have later-onset forms.
Cell or gene therapy options - Condition guide
DCLRE1C-associated Artemis-deficient severe combined immunodeficiency
Artemis-deficient SCID is caused by DCLRE1C variants that impair DNA repair needed to build immune-cell receptors. Severe forms lack effective T- and B-cell immunity; partial defects can present differently or later.
Donor transplant option - Condition guide
IL2RG-associated X-linked severe combined immunodeficiency
IL2RG-associated SCID disrupts immune signaling needed for T-cell and natural-killer-cell development. B cells may be present but function poorly. Some IL2RG variants cause less typical, later presentations.
Donor transplant option - Condition guide
IL7R-deficient severe combined immunodeficiency
IL7R-deficient SCID is a genetic disorder that prevents normal T-cell development. B cells and natural-killer cells are typically present, but the lack of effective T-cell immunity leaves a child vulnerable to serious infection.
Donor transplant option - Condition guide
JAK3-deficient severe combined immunodeficiency
JAK3-deficient SCID is a recessive genetic disorder that disrupts immune signaling. T cells and natural-killer cells are usually profoundly reduced, while B cells may be present but cannot provide normal protection.
Donor transplant option - Condition guide
RAG1 deficiency
RAG1 deficiency impairs the DNA rearrangement needed to build T- and B-cell receptors. Severe loss of function can cause SCID; partial function can cause Omenn syndrome or later combined immunodeficiency with infection and immune dysregulation.
Donor transplant option - Condition guide
RAG2 deficiency
RAG2 deficiency impairs the DNA rearrangement needed to build T- and B-cell receptors. Severe loss of function can cause SCID; partial function can cause Omenn syndrome or later combined immunodeficiency with infection and immune dysregulation.
Donor transplant option
Understanding can become action.
Some patients need a blood stem cell donor. Others receive different treatment. Wherever your interest began, you can help JBF reach more people who may be able to donate.
Explore the official registry serving where you live. It explains who can join, how registration works and what donation involves.
Find your official registryIf joining is not right for you, a gift to the Jada Bascom Foundation supports education, outreach and referrals to official registries.
Donate to JBFSources and further reading
- Inborn Errors of Immunity — EBMT Handbook / NCBI Bookshelf
- Adenosine Deaminase Deficiency — GeneReviews / NCBI Bookshelf
- X-Linked Severe Combined Immunodeficiency — GeneReviews / NCBI Bookshelf
