Sa. Gayther et al., GERMLINE MUTATIONS OF THE BRCA1 GENE IN BREAST AND OVARIAN-CANCER FAMILIES PROVIDE EVIDENCE FOR A GENOTYPE-PHENOTYPE CORRELATION, Nature genetics, 11(4), 1995, pp. 428-433
Mutations in the BRCA1 gene, discovered in 1994, are associated with a
n 80-90% lifetime risk of breast cancer. We have analysed 60 families
with a history of breast and/or ovarian cancer for germline mutations
in BRCA1. Twenty-two different mutations were detected in 32 families
(53%), of which 14 are previously unreported. We observed a significan
t correlation between the location of the mutation in the gene and the
ratio of breast to ovarian cancer incidence within each family. Our d
ata suggest a transition in risk such that mutations in the 3' third o
f the gene are associated with a lower proportion of ovarian cancer. H
aplotype analysis supports previous data which suggest some BRCA1 muta
tion carriers have common ancestors; however, we have found at least t
wo examples where recurrent mutations appear to have arisen independen
tly.