Genomic alterations in histopathologically normal breast tissue from BRCA1 mutation carriers may be caused by BRCA1 haploinsufficiency.
Multiple biopsies of normal breast tissue from 10 BRCA1 mutation carriers have been analyzed using array-based comparative genomic hybridization. Normal breast tissue from five age-matched control subjects without a family history of breast cancer was included for reference purposes. We repeatedly found multiple low copy number aberrations at a significantly higher frequency in histopathologically