The gene for Breast Cancer (BRCA) is present on chromosome:
Women with hereditary breast-ovarian cancer susceptibility have mutation in tumor suppressor BRCA genes—

BRCA-1 (located on chromosome 17q) 
BRCA-2 (located on chromosome 13q)

The risk in BRCA-1 carriers is higher compared to that in BRCA-2 carriers.
Mohan H. Textbook of pathology. Jaypee Brothers Medical Publishers; 2015. Edition 7. Page 731
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