1) Question: How do mutations in the BRCA1 and BRCA2 genes contribute to an increased risk of breast

and ovarian cancer?

Answer: Mutations in the BRCA1 and BRCA2 genes disrupt the normal function of DNA repair

mechanisms, leading to the accumulation of genetic alterations in cells. As a result, affected individuals

have a higher likelihood of developing breast and ovarian cancer due to impaired DNA damage response.

2) Question: Explain how mutations in the CFTR gene result in the development of cystic fibrosis.

Answer: Mutations in the CFTR gene cause protein misfolding, resulting in dysfunctional chloride ion

channels on the surface of cells. This leads to thickened mucus secretion, impaired lung and pancreatic

function, and other characteristic features observed in cystic fibrosis.

3) Question: What is the role of the TP53 gene in preventing the development of cancer?

Answer: The TP53 gene encodes the p53 protein, which plays a crucial role in preventing cancer

development. It acts as a tumor suppressor by regulating cell cycle arrest, DNA repair, and apoptosis.

Mutations in TP53 can lead to the accumulation of genetic damage and an increased risk of cancer.

4) Question: How does a mutation in the HTT gene result in Huntington's disease?

Answer: A mutation in the HTT gene causes an abnormal expansion of a DNA segment, resulting in the

production of a toxic protein called mutant huntingtin. This protein aggregates and damages neurons,

leading to the progressive neurodegeneration observed in Huntington's disease.

5) Question: Discuss the connections between mutations in the LDLR gene and familial

hypercholesterolemia.

Answer: Mutations in the LDLR gene impair the ability of cells to remove low-density lipoproteins (LDL)

from the bloodstream. This leads to elevated levels of LDL cholesterol, increasing the risk of cardiovascular

diseases, such as atherosclerosis, associated with familial hypercholesterolemia.