Assessment of the loss of the wild-type BRCA1 allele in tumor DNA. A-C) The two D17S855 alleles (al_147 and al_155) present in the peripheral blood leukocytes (PBLs) DNA of the patient are indicated. A strong reduction of the peak corresponding to the al_155 allele is observed in both the ACC and the IDC DNA (indicated by the arrows). D-F) BRCA1 sequence analysis. The site of the germline c.4484 G>T mutation is indicated by the arrows. A reduction of the wild-type G allele is visible in both the ACC and IDC DNA.