Author: Nat Pernick, M.D. (see Authors page)

Revised: 16 October 2015, last major update February 2014

Copyright: (c) 2003-2015,, Inc.

PubMed Search: ARID1A
  • AT Rich Interactive Domain 1A (SWI-like) tumor suppressor gene at 1p36.11 encodes BAF250A, a member of the SWI/SNF ATP-dependent chromatin-remodeling complexes (J Gynecol Oncol 2013;24:376)
  • Involved in tissue development and cellular differentiation
  • Inactivation of components of chromatin-remodeling complex are associated with malignancy
    • Most ARID1A somatic mutations are frame-shift or nonsense mutations that contribute to mRNA decay and loss of protein expression
    • 5% of ARID1A mutations are in-frame insertions or deletions (indels) that involve only a small stretch of peptides (Neoplasia 2012;14:986)
Clinical Features

Gene map

Regulation of chromatin structure

Micro Images

Images hosted on other servers:

Cervix: borderline seromucinous tumors

Ovary: clear cell carcinoma (A, B)

Ovary: endometriotic cyst and associated well-differentiated endometrioid carcinoma

Stomach: gastric carcinoma

Uterus: endometrioid carcinoma

Uterus: endometriosis (G-I)

Images hosted on
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Ovary: carcinomas

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Ovary: clear cell adenofibroma

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Ovary: clear cell carcinoma

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Ovary: endometriosis adjacent
to clear cell carcinoma

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Uterus: endometriosis

Positive Staining - Normal
  • Normal tissue shows ARID1A staining
Negative Stains
  • Various tumors (see above) show loss of ARID1A staining