Interviewee: Mary-Claire King. Mary-Claire King talks about the value of using the centuries-old tool of family pedigrees to gain insight into patterns of inheritance of genetic disorders. (DNAi Location: Applications > Genes and medicine > Gene hunting > Families and pedigrees)

Finding BRCA1 and BRCA2 has relied critically on families who have suffered a great deal of breast and ovarian cancer, being willing to participate in the project. Here is an example. This is a pedigree of a family with whom we've worked for a long while. On this pedigree or family tree, circles represent women, squares represent men, and filled symbols represent cancer. So this is a woman with breast cancer in her forties, a woman with breast cancer at thirty who died of her breast cancer, that's the line through the symbol. This woman and her sister with breast cancer have two other sisters who have still had no cancer, thus far. The mutation in this family must have been inherited through the father, here, who had prostate cancer when he was eighty, because there are so many other relatives through the father, with breast and ovarian cancer, many. This woman and her daughter were concerned for the sake of the grand-daughters about the mutation that might be responsible for breast and ovarian cancer in the family. We have been able by working with this entire family, 150 people in the family, over a long period of time, to sort it out. So now this sister knows that despite all of the breast and ovarian cancer in the family, that she has a completely normal BRCA1 and BRCA2 sequence, she does not share the BRCA1 mutation that was inherited by her two sisters and by this niece, and by all these other breast and ovarian cancer patients. This woman needs to now decide if she wants to find out as well, she has a 50-50 chance of having inherited the family's BRCA1 mutation.

mary claire king,ovarian cancer patients,brca1 and brca2,brca1 mutation,family pedigrees,pedigress,patterns of inheritance,hereditary cancer,breast cancer,location applications,ovarian cancer,dnai,grand daughters,prostate cancer,genetic disorders,interviewee,forties,two sisters,niece,mutations