title: Mutational analysis of BARD1 in familial breast cancer patients in Japan.
abstract: Since BRCA1,which is a breast cancer susceptibility gene, form heterodimers with BARD1, it is speculated that BARD1 mutations might affect the function of BRCA1, contributing to breast carcinogenesis. Thus, in the present study, we have conducted mutational analysis of BARD1 in familial breast cancer patients (n=60) who were tested negative for both BRCA1 and BRCA2 germline mutations. We have been unable to show any clearly deleterious mutations but identified four missence mutations (Ser/Cys 241, Arg/Ser 378, Asn/Ser 470, Val/Met 507), one silent mutation (His/His 506), and one frameshift (in-frame) mutation (1139del21bp). Of these six mutations, one (Asn/Ser 470) was considered as a putative germline mutation since such a mutation was not observed in any of the healthy controls (n=152) but the other five mutations were considered as common genetic polymorphisms since they were frequently observed in the healthy controls. These genetic polymorphisms were further analyzed in their association with breast cancer risk by a case-control study using the population-based breast cancers (n=143) and healthy controls (n=155), which showed that carriers of the variant allele Met at codon 507 are significantly associated with the increased risk of breast cancer (adjusted odds ratio=2.05, 95% confidential interval=1.01-4.16) in postmenopausal women and that the other genetic polymorphisms are not associated with breast cancer risk. These results suggest that BARD1 mutations are responsible for, if any, a very small number of familial breast cancers. Genetic polymorphism of BARD1 (Val/Met 507) could be useful in the selection of postmenopausal women at a high risk for developing breast cancer.
authors.affiliation: Department of Surgical Oncology, Graduate School of Medicine, Osaka University, 2-2-E10, Yamada-oka, Suita, 565-0871, Osaka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ishitobi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Miyoshi
authors.forename: Seiichi
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Chiyomi
authors.initials: C
authors.lastname: Egawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tamaki
authors.forename: Morito
authors.initials: M
authors.lastname: Monden
authors.forename: Shinzaburo
authors.initials: S
authors.lastname: Noguchi
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation; D006801:Humans; D007564:Japan; D008593:Menopause; D011110:Polymorphism, Genetic; D012306:Risk; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases
chemical_list: D002352:Carrier Proteins; D025521:Tumor Suppressor Proteins; C102449:BARD1 protein, human; D044767:Ubiquitin-Protein Ligases