How accurate is genetic testing in assessing risk?
Genetic testing is highly controversial. It is important to remember that genetic tests are not 100% accurate: as many as 30% of BRCA1 and BRCA2 mutations are not identified by tests. More than 200 different kinds of mutations have already been identified in BRCA1 and 2 genes, and only a very few of these are known to be connected to the risk of breast cancer. Hence, in order to determine whether a BRCA mutation increases the risk of breast cancer for a particular individual, it is necessary to conduct family tests in which the individuals diagnosed with breast or ovarian cancer are tested for particular mutations. Who might consider having a genetic test for a cancer gene mutation? Genetic testing is a process for families, not for individual women. Because there are so many BRCA1 and 2 mutations, it is important to investigate a particular mutation over generations and to identify its connection to the incidence of breast or ovarian cancer in that family. Families that might wish to
