Activity Instructions Analyze the data presented in the graph and table below. Then write a summary addressing the following:

1. The histogram below shows the total estimated new breast cancer cases diagnosed in 2003. (first image)

2. The results in this table below are from a 2007 study investigating BRCA mutations in women diagnosed with breast cancer. All of the women in the study had a family history of breast cancer. (second image)

*A mastectomy is the surgical removal of one or both breasts, either partially or fully. An oophorectomy is the surgical removal of an ovary or ovaries.

Things to address in your summary essay:

-Describe how mutations lead to genetic variations.
-Which appears to be more dangerous: the BRC1 or BRC2 mutation?
-Analyze a woman’s risk of dying of cancer if she carries a mutated BRC1 gene.
-How do heredity and inheritance relate to the data presented in these charts?
-What data would you need to see in order to draw conclusions about the effectiveness of preventive surgeries?
-What does the age at diagnosis tell you about the mutation?
-Explain how breast-cancer genes are still present in the population, despite cancer-related surgeries and deaths.

Describe how mutations lead to genetic variations.

Mutations are changes in the DNA sequence of any organism. These DNA sequence comprise genes which control all the traits of an organism such as height, weight, eye color or which specific protein will be formed in body at which time. Everything is controlled by tiny pieces of DNA. If there occurs any change in the DNA sequence of an organism, it can be lethal to it, for example: In case of cancerous mutations where proteins controlling cell division are badly affected. Other mutations are simply passed to the offspring leading to genetic variations in the offspring. This is how mutations leads to the changes in genetic of an organism.

Which appears to be more dangerous: the BRC1 or BRC2 mutation?

The BRC1 and BRC2 are mutations or changes in the BRCA gene of humans mostly females. BRCA gene is basically a tumor suppressor gene which in some cases undergo mutations of different types. Some of which can be unharmful while BRC1 and BRC2 are typically very dangerous mutations because they increase the chances of a woman to develop breast cancer. Woman with BRC1 and BRC2 mutations have five times more risk of developing the breast cancer than other women. Studies suggest that BRC1 mutation is more dangerous than BRC2 mutations because a greater number of patients seen have BRC1 kind of mutation. Moreover, BRCA1 is associated with triple-negative breast cancer response in which a person cannot be fully treated with some drugs like which does not respond to hormonal trastuzumab and hormonal treatments.  

Analyze a woman’s risk of dying of cancer if she carries a mutated BRC1 gene.

The risk of a woman to die with cancer due to with BRC1 mutation are quite high. This is because 18 percent of the women which develop breast cancer due to BRC1 mutation die while only 2.8 percent of the women who develop breast cancer due to BRC2 mutations die. This indicates substantially higher risk of BRC1 patients of dying as compared to BRC2 patients.

What data would you need to see in order to draw conclusions about the effectiveness of preventive surgeries?

There are several preventive surgeries used to prevent the chances of breast cancer in women. However, the genetic history of a person and her family’s genetic history is important to see before drawing some effective preventive surgery.

What does the age at diagnosis tell you about the mutation?

By looking at different cases of breast cancers and analyzing the data of different countries, we noticed that,  the onset of disease takes several years because it is a genetic level mutation and the onset of mutation starts in earlier years of a woman’s life however she fully becomes a victim and notices it in late years of her life. This is why it cannot be easily diagnosed in early years even it is present there.

Explain how breast-cancer genes are still present in the population, despite cancer-related surgeries and deaths.

The genes responsible for breast cancer such as BRC1 and BRC2 are inherited from parents to offspring in a dominant fashion which means only one copy of gene is enough for the onset of the disease. Also because the disease is caused due to genetic level mutations, even if the doctors remove the cancers through surgeries they are not able to remove each and every affected gene from an organism which is passed from parents to offspring and still present in population.

-- be sure to paraphrase if your assignment is on FLVS! good luck :)

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