Question

Given that TP53 is a recessive gene and is not located on the X chromosome, why would people who inherit just one mutant copy of a recessive tumor-suppressor gene be at higher risk of developing cancer than those without the recessive gene?

Given that is a recessive gene and is not located on the X chromosome, why would people who inherit just one mutant copy of a recessive tumor-suppressor gene be at higher risk of developing cancer than those without the recessive gene?

The recessive the TP53 gene is associated with the mutation in BAX. This mutation leads to increased risks of abnormal cell cycle and deferred apoptosis which, in turn, may lead to cancer.

Two copies of the normal gene result in special conformation of a chromosome that protects TP53 gene from mutations, whereas individuals with one functional copy would be more vulnerable to mutations and would more likely have cancer.

Individuals with two copies of the gene would need to experience separate mutations in both copies to develop cancer, whereas individuals with one functional copy would only need a single mutation.

The recessive TP53 gene influences expression of the other tumor-suppressor gene. A reduced amount of the p53 protein would be associated with higher risk of abnormal functioning of other tumor suppressors and a higher risk of developing cancer.

Answer 1

The TP53(tumor protein p53) gene forms the tumor suppressor protein which regulates fast or uncontrolled cell division. This protein is found in the nucleus of the cells and it binds to the DNA to regulate the cell division. In case of damage to the DNA, it either repairs the damage or when the damage cannot be repaired, it signals the cell for apoptosis(programmed cell death) to prevent the formation of tumors. The mutation in a single allele of this gene although is recessive, but acts as a dominant negative. The mutant protein formed by the mutant allele of the TP53 gene prevents the functioning of the normal protein produced by the non-mutant allele. The suppressor effect of the normal protein is itself suppressed by the mutant protein formed. Reduction in the p53 protein increases the susceptibility of an individual for the development of cancer. The last statement is correct.