PIK3CD

phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta

3 disorders 3 causative 1p36.22 gene with protein product

HGNC:8977 Monarch NCBI Gene 5293 ENSG00000171608 UniProt O00329 OMIM 602839

Aliases: p110D.

Normal function · from ai-gene-review (O00329, commit 79fe13b38970) · AI-generated, not KB evidence

PIK3CD encodes p110delta, the leukocyte-enriched catalytic subunit of class IA phosphoinositide 3-kinase delta. In p85-family regulatory complexes, p110delta phosphorylates membrane phosphoinositides, especially PI(4,5)P2, to generate PIP3 downstream of immune receptors including BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40, Fc receptors, and cytokine/growth-factor receptors. The core curatable function is PIP3-producing lipid kinase activity in PI3K/AKT immune receptor signaling; broad immune phenotypes, chemotaxis, angiogenesis, and migration annotations are supported contextual outputs rather than the core molecular function.

PIK3CD/p110delta is the leukocyte-enriched class IA PI3K catalytic subunit that forms p85-family regulatory complexes and generates PIP3 from PI(4,5)P2 at receptor-activated membranes.

molecular function: 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity · directly involved in: phosphatidylinositol 3-kinase/protein kinase B signal transduction; B cell receptor signaling pathway; T cell receptor signaling pathway; T cell costimulation · locations: plasma membrane · in complex: phosphatidylinositol 3-kinase complex, class IA

In the knowledge base · computed from kb/ at build time

Disorders

Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.

Disorder	Relationship	Where the gene appears
Activated PI3K-delta syndrome	causative germline	mechanism: PI3K-delta pathway hyperactivation subtype: APDS1 scoped to subtype: APDS1
Autosomal Agammaglobulinemia	causative germline	mechanism: Reduced PI3K p110-Delta Function subtype: PIK3CD scoped to subtype: PIK3CD
Immunodeficiency 14B, Autosomal Recessive	causative germline loss of function	mechanism: Biallelic PIK3CD Loss of Function

ClinGen gene–disease validity · snapshot 2026-10-03 · matched to entries by MONDO

An entry matches when ClinGen's MONDO disease is the entry's own disease term, a subtype term, or an exact-match mapping. An amber status marks an entry ClinGen supports the gene for (Definitive, Strong or Moderate) whose own record does not type it. A Limited, Disputed or Refuted tier on such an entry is not a gap.

ClinGen disease	MOI	Classification	dismech entry
immunodeficiency 14 MONDO:0014222	AD	Definitive 2022-04-19	Activated PI3K-delta syndrome causative
immunodeficiency 14b, autosomal recessive MONDO:0023655	AR	Definitive 2022-04-19	Immunodeficiency 14B, Autosomal Recessive causative

Identity from HGNC (snapshot 2026-10-01). Page layers are described in the gene pages documentation.