Genetics: Analysis of Genes and Genomes: Keyword Hot Links for chapter 15

Among 400 people, about 200 will develop at least one tumor of the colon (large bowel), 20 of these cases will progress to malignancy, and 1 will be associated with an inherited genetic abnormality. Among the inherited forms of colon cancer, two important types are familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). They demonstrate the difference between tumor initiation and tumor progression. Patients with FAC develop thousands of colon polyps, only a few of which progress to cancer, whereas patients with HNPCC have only a few polyps, but each has a high probability of progressing to cancer. Consult this keyword site to learn more about these and other types of colon cancer.

Mutations in the human genes to %11% and BRCA2 are each major genetic risk factors for hereditary breast cancer in women and prostate cancer in men. Among carriers of either mutation, the risk of breast cancer by age 70 is 56 percent, that of ovarian cancer 16 percent, and that of prostate cancer 16 percent. The frequency of carriers differs among population groups. Among Ashkenazi Jews, about one person in 50 carries a mutation in either BRCA1 or BRCA2. These keyword site contain a great deal more information on what is known about the genetics and molecular biology of these genes.

In the United States the frequency of %%1%% is about 1 in 23,000 live births. It is a disease of young children, because the great majority of cases are diagnosed prior to the age of 5. In many cases there are treatment options other than surgical removal of the eye. These include cryotherapy to destroy the cancer cells with extreme cold, laser light to target the tumors and the surrounding blood vessels that feed them, and radiation and chemotherapy. This keyword site aims to provide information and links for anyone interested in any aspect of the disease.