Stains
ARID1A

Author: Nat Pernick, M.D.

Revised: 26 March 2018, last major update February 2014

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: ARID1A
Cite this page: Pernick, N. ARID1A. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/stainsarid1a.html. Accessed July 21st, 2018.
Definition / general
  • 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
Diagrams / tables

Gene map

Regulation of chromatin structure

Microscopic (histologic) 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)

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