ABSTRACT
DNA is an essential carrier of genetic information in the development, functioning and reproduction processes of all living organisms. Adaptation in the chemical structure of DNA is known as DNA damage. Mainly, DNA damage is caused two types of factors: endogenous and exogenous. DNA damage affects the diverse systems of the body, including the reproductive system, cardiovascular system, lymphatic system and nervous system, as well as causes cancer, ageing and various other diseases. DNA repair proceeds through various mechanisms, such as base excision repair (BER), nucleotide excision repair (NER), mismatch excision repair (MMR) and double-strand break repair (DSBR). DNA repair defects are visualised in virtually all the diseases portrayed as accelerated ageing diseases, where various tissues, organs or systems of the human body age untimely. Persons with an innate impairment in DNA repair capability are often at an amplified risk of cancer. In case of a mutation in a DNA repair gene, it is either not be articulated, or if it is be articulated, it does so in an altered form. In such a case, the repair function is likely deficient and, as a corollary, the damage tends to accumulate. Such DNA damage can cause errors during DNA synthesis, which leads to mutations, some of which may give result in cancer.
