BRCA2 and Alzheimer disease: Compared with rectal AD, anal AD had a significantly higher frequency of actionable GAs in ERBB3 (22.2% v 1.8%, P < .01), MYC (20.0% v 8.4%, P < .01), and BRCA2 (6.7% v 1.5%, P < .01) and had a significantly lower frequency of actionable GAs in APC (8.8% v 84.6%, P < .01).