ARID1A

AT-rich interaction domain 1A

17 disorders 12 untyped 3 somatic driver 1 no genetic record 1 cooperating 1p36.11 gene with protein product

HGNC:11110 Monarch NCBI Gene 8289 ENSG00000117713 UniProt O14497 OMIM 603024

Previous symbols: C1orf4, SMARCF1. Aliases: B120, P270, C10rf4, BAF250, BAF250a.

Normal function · from ai-gene-review (O14497, commit 79fe13b38970) · AI-generated, not KB evidence

ARID1A (BAF250A/p270) is a nuclear DNA-binding and assembly subunit of canonical mammalian SWI/SNF (cBAF) chromatin-remodeling complexes. Its ARID domain binds DNA without an established AT-rich sequence preference, while other regions associate with complex components and transcriptional regulators. ARID1A-containing complexes couple substrate engagement and regulatory recruitment to ATP-driven nucleosome remodeling by SMARCA4 or SMARCA2, supporting context-dependent transcriptional activation and repression. ARID1A and ARID1B occupy alternative positions in cBAF assemblies. ARID1A also participates in TOP2A-associated chromosome decatenation and contributes to developmental gene-regulatory programs; altered ARID1A function is associated with developmental disorders and cancer.

Bind DNA and supply structural and recruitment contacts within ARID1A-containing cBAF complexes, contributing to nucleosome remodeling and transcriptional regulation. ARID1A does not itself supply the SMARCA2/4 ATPase activity.

molecular function: DNA binding · contributes to molecular function: ATP-dependent chromatin remodeler activity · directly involved in: chromatin remodeling; regulation of transcription by RNA polymerase II · locations: nucleoplasm · in complex: SWI/SNF complex

Promote receptor-dependent transcription as a coactivator within human SWI/SNF complexes. Human hOsa1 enhances steroid-receptor reporter activation in the inspected cellular assays; this function cooperates with DNA engagement and complex recruitment, and does not imply activation of every ARID1A target.

molecular function: transcription coactivator activity · directly involved in: positive regulation of DNA-templated transcription · locations: nucleoplasm · in complex: SWI/SNF complex

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
Adenomyosis	somatic driver
Endometriosis	somatic driver somatic
Gastric Adenocarcinoma	somatic driver somatic	mechanism: EBV-Driven Hypermethylation and Checkpoint Ligand Amplification scoped to subtype: EBV-positive
Salivary Gland Polymorphous Adenocarcinoma	cooperating somatic	mechanism: PRKD Family Gene Rearrangement
Chordoma	untyped Somatic Epigenetic Dysregulation
Clear Cell Ovarian Carcinoma	untyped Recurrent tumor suppressor mutation with frequent biallelic loss
Coffin-Siris syndrome	untyped Causative	mechanism: BAF/SWI-SNF chromatin remodeling dysfunction; Cardiac neural crest dysregulation from BAF dysfunction; Cranial neural crest specification defect from ARID1A-BAF/ZIC2 axis; Mesenchymal stem cell quiescence loss and tooth root progenitor defects subtype: CSS2 scoped to subtype: CSS2
EBV-Associated Gastric Cancer	untyped Somatic Mutation
Endometrial Endometrioid Adenocarcinoma	untyped Recurrent somatic chromatin remodeling driver alteration somatic
Gallbladder Cancer	untyped Somatic Loss-of-Function Mutation
Gastric Cancer H. pylori Associated	untyped Somatic Mutations
Hepatocellular Carcinoma	untyped Somatic Loss of Function
IDH-Mutant Cholangiocarcinoma	untyped Co-occurring Mutations
Ovarian Endometrioid Carcinoma	untyped Loss-of-function mutation	mechanism: ARID1A and SWI/SNF Chromatin Remodeling Loss
Sezary Syndrome	untyped Tumor Suppressor Loss
Transitional Cell Carcinoma	untyped somatic
Endometrial Carcinoma	no genetic record	mechanism: PTEN PI3K Pathway Dysregulation

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
Coffin-Siris syndrome MONDO:0015452	AD	Definitive 2021-07-07	Coffin-Siris syndrome untyped

Mechanism modules · computed from kb/

epigenetic_machinery_neurodevelopmental_dysregulation via Coffin-Siris syndrome

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