Diseases caused by dna damage

Major diseases caused by DNA damage.

1. Diseases caused by DNA damage By M.Vharshini B.Sc. Biomedical sciences Sri Ramachandra University

2. DNA damage  is an alteration in the chemical structure of  DNA , such as a break in a strand of DNA, a base missing from the backbone of DNA, or a chemically changed base such as  8-OHdG . Damage to DNA that occurs naturally can result from  metabolic  or  hydrolytic  processes. DNA damage induces sequential responses to either repair the damage or activate apoptosis. Introduction

3. Diff b/w DNA Damage & Mutation

4. Defects in this critical response to DNA damage leads to wide array of human pathologies that include : Cancer predisposition, Inflammation responses, Cell Ageing and Neurodegeneration.

5. Cancer & Cell Ageing

6. Mechanism

7. Neurodegeneration is the common feature of many nervous system and aging diseases, such as   Huntington Disease (HD),   Parkinson’s disease  (PD) and Alzheimer’s disease (AD) Neurodegeneration and DNA damage

8. Infections and chronic inflammations have been recognized as important risk factors for carcinogenesis and malignancies. Inflammation can be induced not only by chronic infection but also endogenous and exogenous factors. Chronic inflammation accounts for approximately 25% of human cancers. Under inflammatory conditions, reactive oxygen species(ROS) & reactive nitrogen species(RNS) are generated from inflammatory & epithelial cells. ROS can induce the formation of oxidative DNA lesion products which is considered to be mutagenic DNA damage in chronic inflammation

9. Deletion of DNA segments is the predominant form of radiation damage in cells that survive irradiation. It may be caused by any of two reasons: 1) Mispair of two separate double strand breaks in DNA molecule with join of the two outer ends and loss of the fragment between the breaks. 2)The process of cleaning (enzyme digestion of nucleotides- the component molecules of DNA) of the broken ends before rejoining to repair one double strand break. DNA damage caused my Ionising radiation

10. Reference http://www.archivesofmedicine.com/medicine/dna-damage-and-repair-neurodegeneration-and-the-roleof-pur-in-dna-repair.php?aid=6739 https://en.wikipedia.org/wiki/Free_radical_damage_to_DNA http://www.ncbi.nlm.nih.gov/pubmed/26255941 http://www.asianscientist.com/2014/11/in-the-lab/dna-damage-leads-cancer/ http://www.sciencedirect.com/science/article/pii/S0092867407011415

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