DNA repair genes

DNA repair genes are a group of genes that encode for proteins involved in the process of DNA repair. These genes play a crucial role in maintaining the integrity of the genetic material and preventing the accumulation of DNA damage and mutations that can lead to various diseases, including cancer.

Function

The primary function of DNA repair genes is to correct any errors that occur during DNA replication. These errors can be caused by a variety of factors, including exposure to radiation, chemicals, or simply due to mistakes made by the DNA polymerase during replication. The proteins encoded by these genes recognize and repair these errors, thereby preventing the accumulation of mutations and maintaining the stability of the genome.

Types of DNA Repair Genes

There are several types of DNA repair genes, each involved in a different aspect of the DNA repair process. These include:

• Mismatch repair (MMR) genes: These genes are involved in the repair of errors that occur during DNA replication, such as mismatched bases or small insertions and deletions.

• Nucleotide excision repair (NER) genes: These genes are involved in the repair of bulky DNA lesions caused by exposure to ultraviolet light or certain chemicals.

• Base excision repair (BER) genes: These genes are involved in the repair of small, non-helix-distorting base lesions, such as those caused by oxidation or alkylation damage.

• Double-strand break repair (DSBR) genes: These genes are involved in the repair of double-strand breaks in the DNA, which can be caused by exposure to ionizing radiation or certain chemicals.

Diseases Associated with DNA Repair Genes

Mutations in DNA repair genes can lead to a variety of diseases, most notably cancer. For example, mutations in the MMR genes MLH1 and MSH2 are associated with Lynch syndrome, a hereditary form of colorectal cancer. Similarly, mutations in the DSBR genes BRCA1 and BRCA2 are associated with hereditary breast and ovarian cancer.

In addition to cancer, mutations in DNA repair genes can also lead to a number of rare genetic disorders characterized by increased sensitivity to DNA-damaging agents and a high risk of cancer. These include xeroderma pigmentosum (XP), caused by mutations in NER genes, and ataxia-telangiectasia (A-T), caused by mutations in the DSBR gene ATM.

See Also

• DNA damage (naturally occurring)
• DNA replication
• Mutagen
• Oncogene