DNA Mutation

Heritable changes in the DNA sequence has been defined as DNA mutation.  DNA damaging agents such as X-rays, UV-rays or chemical might cause DNA mutation. Natural processes in the cell may result a spontaneous mutation and reaction between mutagen and DNA can cause induced mutation (KSU, n.d.). Hereditary mutations or germline mutation can be passed to next generation from parent to child and it remains in the individual’s body throughout the life however somatic or acquired mutation caused by external factors cannot be passed onto next generation (NIH, 2014).

Mutation can be transition or transversion. In transition, purine nucleotide is changed into purine and pyrimidine into pyrimidine whereas purine is changed into pyrimidine and vice versa in transversion mutation (Chuck and Chao, n.d.). Insertion, deletion and substitution are DNA mutation mechanisms. Nitrogenous base is replaced in substitution by other bases, deletion is the loss of the block of one or more DNA pairs and insertion is the addition of the block of one or more DNA (Berkeley, n.d.).

Mutation can have health effects on human body. Normal development of body and development of embryo at its early stages can be affected by mutation (NIH, 2014). Mutation can also induce protein malfunction and genetic disorder (NIH, 2014). Deletion occurring between repeated sequences has resulted changes in mitochondrial structure and disorder of central nervous system known as mitochondrial encephalomyopathies (immuneweb, n.d.).

Depurination and deanimation can lead to spontaneous lesions causing DNA damage and mutation. Depurination is the interruption of the glycosidic bond between the base and deoxyribose and the subsequent loss of a guanine and an adenine residue from the DNA. Deanimation includes the conversion of G-C pair into an A-T pair (Immuneweb, n.d.).

 

References

Berkeley (n.d.) Types of Mutations and their impact on protein function [Online] Available at http://www.mcb.berkeley.edu [Accessed on 22 May 2014].

Chuck, G. and Chao, K (n.d.) Mutation [Online] Available at http://www.memocgu.tw [Accessed on 13 May 2014].

Immuneweb (n.d.) Mechanisms of Gene Mutation [Online] Available at http://www.immuneweb.com [Accessed on 25 May 2014].

KSU (n.d.) DNA Mutation [Online] Available at http://www.faculty.csu.edu.sa [Accessed on 22 May 2014].

Marinus, M.G. (n.d.) Mutation [Online] Available at http://www.users.umass.edu [Accessed on 13 May 2014].

National institute of Health (NIH) (2014) Mutation and Health [Online] Available at http://www.ghr.nlm.nil.gov [Accessed on 22 May 2014]

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