Question

How could a person that was a carrier for a BRCA1 cancer related allele not get cancer?

A mutation occurs in a tumor suppressor gene and makes a cancerous cell. How can a mutation in this kind of gene result in cancer?

Answer 1

Ans.BRCA 1 and BRCA 2 are the Genes which play a role in inheritance of breast cancer and ovarian cancer . Although they both are tumor suppressor gene causing control of cell death and its growth it is a mutation in them results in cancer . So , if a person inherits these Genes mutation the person may not get cancer because for cancer second mutation in them is needed to knock or get off their function. A tumor suppressor gene function to control cells growth , cell death ,DNA repair .They can cancer only when they inactivate, mutation happen to them (mutation should be in both the alleles).Loss in their heterozygosity or methylation in their promoter can cause suppression of the gene transcription. These both are the ways of inactivating tumor suppressor gene.