Genes and Mutations

Get to know the main players causing breast cancer.

Genes

BRCA1

Gene which is linked to hereditary breast cancer.

Features:

  • Encodes around 1863 amino acids.
  • It can cause frameshift , nonsense deletion mutations.
  • Short telomeres can increase the chance of cancer.
  • It has a strong link between BRCA1 and triple negative breast cancer .

BRACA2

Mainly plays a role in homologous recombination for Dna repair.

Features:

  • It is linked with loss of heterozygosity in 80% percent of cases.
  • Around 1853 mutations reported.
  • The chance of mutation could increase if the patients inherits deletrious mutation.
  • Hypermethylation of BRACA2 gene is a rare case .

TP53

This gene encodes the p53 tumor suppersor protein.

Features:

  • Mutations reported in 20-40% of breast cancer cases.
  • Middle aged women develop breast cancer due to mutated alleles.
  • TP53 plays a major role in Dna repair and cell cycle regulation.

Other Genes

ATM Gene

Mutations in the ATM gene can be a sign to high risk of breast cancer.

Features:

  • 1% of the population in the US carry one copy of mutated ATM gene.
  • High risk of breat cancer
  • Half as much ATM protein is produced by cells with only one functional copy, which results in ineffective DNA repair.

BARD1 Gene

BARD1 and BRACA1 gene work simultaneously in Dna repair which is important for preventing cancer development.

Features:

  • BARD1 directs BRCA1 to locations where DNA strand breaks by binding and stabilizing it.
  • BARD1 interacts with TP53 to limit cell division and promote apoptosis, or controlled cell death.

Mutation Prognosis

HER2 oncogene

Overexpression can be associated or leads with poor prognosis.

Tumor grade , size , relapse rate are all related with HER2 gene.

Targeted Therapy

In metastatic breast cancer , humanized monoclonal antibodies such as trastuzumab showed an 11.6% response.