Germline mutation of BRCA1 in Japanese breast cancer families.
We analyzed germline mutations of the BRCA1 gene in 18 Japanese breast cancer families and two Japanese breast-ovarian cancer families. In two site-specific breast cancer families, the same mutation was detected; a nonsense mutation at codon 63 encoding a truncated small protein. It was demonstrated that the mutant allele cosegregated with breast cancer patients within a family and was absent in healthy Japanese, suggesting a breast cancer-predisposing allele. The average age at diagnosis was 44 and 55 years in each family with BRCA1 mutation. No bilateral breast cancer patients were present in the BRCA1 mutation-positive families, although five were present in the BRCA1-negative families. No germline mutations of BRCA1 were detected in the two breast-ovarian cancer families examined in this study, although BRCA1 mutation plays a major role in breast-ovarian cancer families in Western countries. Thus, the proportion of families who inherit the mutated BRCA1 allele seems to be small among Japanese breast cancer families and Japanese breast-ovarian cancer families.
Inoue
R
R
Carcinogenesis Division, National Cancer Center Research Institute, Tokyo, Japan.
Fukutomi
T
T
Ushijima
T
T
Matsumoto
Y
Y
Sugimura
T
T
Nagao
M
M
D000328:Adult; D000367:Age Factors; D019313:BRCA1 Protein; D001943:Breast Neoplasms / Q000150:complications / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics*; D010051:Ovarian Neoplasms / Q000150:complications; D010375:Pedigree; D017354:Point Mutation; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D014157:Transcription Factors / Q000235:genetics*
D019313:BRCA1 Protein; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D014157:Transcription Factors