title: A case of familial breast cancer with double heterozygosity for BRCA1 and BRCA2 genes.
abstract: We report an extremely rare case of familial breast cancer with deleterious germline mutations in both BRCA1 and BRCA2 genes, of which, to date, no such case has been reported among Japanese breast/ovarian cancer patients. Genetic testing of the family members indicated that the same double heterozygosity for BRCA1 and BRCA2 genes was transmitted to the paternal cousin, and the same BRCA2 mutation to the younger sister with bilateral breast cancer, younger brother with stomach cancer, and proband's son and daughter without cancer. Immunohistochemical analysis of BRCA protein expression was performed using breast cancer tissues from the proband with double heterozygosity for BRCA1 and BRCA2 genes and from her sibling without BRCA1 mutation but with BRCA2 mutation. There was no staining of either BRCA in the proband and no staining of BRCA2 in the sibling.
authors.affiliation: Department of Surgery and Breast Surgery, Hoshi General Hospital, 2-1-16 Omachi, Koriyama, 963-8501, Japan, nomizu@hoshipital.or.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nomizu
authors.forename: Masami
authors.initials: M
authors.lastname: Matsuzaki
authors.forename: Naoto
authors.initials: N
authors.lastname: Katagata
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sakuma
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Monma
authors.forename: Motonobu
authors.initials: M
authors.lastname: Saito
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Watanabe
authors.forename: Shinichi
authors.initials: S
authors.lastname: Midorikawa
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Yamaguchi
mesh_terms: D019313:BRCA1 Protein / Q000235:genetics* / Q000378:metabolism; D024682:BRCA2 Protein / Q000235:genetics* / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005820:Genetic Testing; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D024682:BRCA2 Protein; C551750:BRCA2 protein, human