Background Germ-line mutations in the BRCA1 and BRCA2 genes predispose women to breast cancer.
BRCA1 mutations are found in approximately 12 percent of women with breast cancer of early onset, and the specific mutation causing a deletion of adenine and guanine (185delAG), which is present in 1 percent of the Ashkenazi Jewish population, contributes to 21 percent of breast cancers among young Jewish women.
The contribution of BRCA2 mutations to breast cancer of early onset is unknown.
Methods Lymphocyte specimens from 73 women with breast cancer diagnosed by the age of 32 were studied for heterozygous mutations of BRCA2 by a complementary-DNA-based protein-truncation assay, followed by automated nucleotide sequencing.
In addition, specimens from 39 Jewish women with breast cancer diagnosed by the age of 40 were tested for specific mutations by an allele-specific polymerase chain reaction.
Results Definite BRCA2 mutations were found in 2 of the 73 women with early-onset breast cancer (2.7 percent ; 95 percent confidence interval, 0.4 to 9.6 percent), suggesting that BRCA2 is associated with fewer cases than BRCA1 (P=0.03).
The specific BRCA2 mutation causing a deletion of thymine (6174delT), which is found in 1.3 percent of the Ashkenazi Jewish population, was observed in 1 of the 39 young Jewish women with breast cancer (2.6 percent ; 95 percent confidence interval, 0.09 to 13. (...)
Mots-clés Pascal : Carcinome, Glande mammaire, Valeur prédictive, Mutation, Prédisposition, Déterminisme génétique, Age apparition, Adulte jeune, Homme, Mesure, DNA complémentaire, Séquençage, Résultat, Femelle, Tumeur maligne, Glande mammaire pathologie, Génétique, Biologie moléculaire, Gène BRCA1, Gène BRCA2
Mots-clés Pascal anglais : Carcinoma, Mammary gland, Predictive value, Mutation, Predisposition, Genetic inheritance, Age of onset, Young adult, Human, Measurement, Complementary DNA, Sequencing, Result, Female, Malignant tumor, Mammary gland diseases, Genetics, Molecular biology
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0299793
Code Inist : 002B20E02. Création : 15/07/1997.