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Trait

Severe combined immunodeficiency

A type of primary immune deficiency that is characterized by a more severe defect in both the T- and B-lymphocyte systems.

HPO HP:0004430

Summary

Also called
Immunodeficiency, severe combined
Body system
Abnormality of the immune system

23 genes linked to Severe combined immunodeficiency

Changes in these genes cause rare conditions in which Severe combined immunodeficiency is seen. Most people with this trait have none of those conditions, and a gene on this list says nothing about anyone's own genome.

GeneHow often it is seenConditions
ADAadenosine deaminaseAlwaysIn 2 conditions
BCL11BBCL11 transcription factor BAlwaysIn 1 condition
CD3DCD3 delta subunit of T-cell receptor complexAlwaysIn 1 condition
MTHFD1methylenetetrahydrofolate dehydrogenase, cyclohydrolase and formyltetrahydrofolate synthetase 1AlwaysIn 1 condition
POLD3DNA polymerase delta 3, accessory subunitAlwaysIn 1 condition
PRKDCprotein kinase, DNA-activated, catalytic subunitAlwaysIn 1 condition
AK2adenylate kinase 2Very often (80–99%)In 1 condition
CHD7chromodomain helicase DNA binding protein 7Very often (80–99%)In 1 condition
DCLRE1CDNA cross-link repair 1CVery often (80–99%)In 2 conditions
IL2RGinterleukin 2 receptor subunit gammaVery often (80–99%)In 2 conditions
IL7Rinterleukin 7 receptorVery often (80–99%)In 2 conditions
NUDCD3NudC domain containing 3Very often (80–99%)In 1 condition
PI4KAphosphatidylinositol 4-kinase alphaVery often (80–99%)In 1 condition
PSMB10proteasome 20S subunit beta 10Very often (80–99%)In 1 condition
RAG1recombination activating 1Very often (80–99%)In 3 conditions
RAG2recombination activating 2Very often (80–99%)In 2 conditions
RMRPRNA component of mitochondrial RNA processing endoribonucleaseVery often (80–99%)In 1 condition
TTC7Atetratricopeptide repeat domain 7AVery often (80–99%)In 2 conditions
EXTL3exostosin like glycosyltransferase 3Often (30–79%)In 2 conditions
LIG4DNA ligase 4Often (30–79%)In 1 condition
PNPpurine nucleoside phosphorylaseOften (30–79%)In 1 condition
PGM3phosphoglucomutase 3Sometimes (5–29%)In 1 condition
JAK3Janus kinase 3Not recordedIn 1 condition

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Broader traits

Combined immunodeficiency

Where this comes from

  • The Human Phenotype Ontology, release 2026-09-01: the trait, its names, its definition and the genes linked to it. Find out more at hpo.jax.org.
  • Data release 2026.10.16-c6eea6bf.

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