Go to the website http://www.cancer.gov and select 'Cancer Types' on the top menu bar. Scroll down to 'Breast Cancer' and click. Select 'Cases & Prevention' from the options. Click 'More information' and select 'BRCA Mutations: Cancer Risk and Genetic Testing'. Use the information on this page to answer the following questions. What are the approximate percentage increases in risk of having breast cancer and of having ovarian cancer for women inheriting harmful mutations of BRCA1 and BRCA2 compared with the risks in the general population?

Verified step by step guidance

1. Understand that BRCA1 and BRCA2 are genes where harmful mutations significantly increase the risk of breast and ovarian cancers compared to the general population.
2. Navigate to the specified website and locate the section on 'BRCA Mutations: Cancer Risk and Genetic Testing' to find reliable, up-to-date statistics on cancer risk associated with these mutations.
3. Identify the baseline risk percentages for breast and ovarian cancer in the general population, which serve as the reference point for comparison.
4. Find the reported lifetime risk percentages for breast and ovarian cancer in women who inherit harmful BRCA1 and BRCA2 mutations.
5. Calculate the approximate percentage increase in risk by comparing the mutation carriers' risk to the general population risk, using the formula: $\mathrm{Percentage\; Increase}=\frac{\mathrm{Risk\; in\; Mutation\; Carriers}}{\mathrm{Risk\; in\; General\; Population}}\times 100$.

Key Concepts

BRCA1 and BRCA2 Genes

BRCA1 and BRCA2 are human genes that produce proteins responsible for repairing damaged DNA. Mutations in these genes can impair DNA repair, leading to increased risks of certain cancers, especially breast and ovarian cancer. Understanding these genes helps explain why some individuals have a higher inherited cancer risk.

Genetic Mutation and Cancer Risk

A genetic mutation is a change in the DNA sequence that can affect gene function. Harmful mutations in BRCA1 or BRCA2 significantly increase the likelihood of developing breast and ovarian cancers compared to the general population. This concept is key to interpreting how inherited mutations influence cancer risk percentages.

Relative Risk and Population Risk Comparison

Relative risk compares the probability of an event, like cancer, occurring in a group with a specific factor (e.g., BRCA mutation) to the probability in the general population. Understanding this helps quantify how much more likely mutation carriers are to develop cancer compared to those without the mutation.