
Genetic mutations are modifications or changes in the sequence of DNA, which serves as the blueprint for the growth and operation of every organism. These changes can affect the four nucleotides that comprise DNA: Adenine (A), thymine (T), guanine (G), and cytosine (C),[1] which form the genetic code that determines our individual traits and attributes with the precise order of these nucleotides.[2] Genetic mutations are intricate and interesting changes that take place in our DNA,[3] and which are essential in determining how living organisms, including humans, live and how they function.[4] Mutation is the greatest source of all genetic variation, providing the raw material for evolution and natural selection.
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Causes of genetic mutations
Genetic mutations can have a variety of causes. During DNA replication, as cells divide and multiply, some mutations happen naturally.[5] We refer to these as spontaneous mutations. Other mutations may result from outside influences like radiation, a reaction to specific chemicals, or even particular diseases.[6]
Types of genetic mutations
- Point Mutations: In these mutations, a single nucleotide in the DNA sequence is replaced, added, or removed. They have the ability to alter the instructions used to construct proteins, resulting in proteins that are changed or are not functional.[7]
- Chromosomal mutations: These mutations result in alterations to the chromosome's composition or quantity. Examples include chromosomal segment deletions, duplications, inversions, and translocations, which involve moving segments from one chromosome to another.[8]
- Frameshift mutations: These changes in the genetic code's reading frame occur when nucleotides are added or removed in multiples other than three. The resultant protein may be drastically altered as a result.[9]
Effects of genetic mutations
Genetic mutations can have a wide range of effects. While some mutations have no discernible impact and can take many generations, especially in the observable characteristics of an organism, others can result in life-threatening diseases.[10] Organisms have mechanisms such as DNA repair to prevent or adjust mutations by reverting the mutated sequence back to its original state.[11] In rare circumstances, mutations can even be beneficial, giving an advantage in particular conditions or settings.
Genetic mutations and genealogy
DNA testing has revolutionized genealogy by analyzing genetic mutations. Mutations that occur over generations create unique genetic signatures, enabling identification of shared ancestry among individuals with matching DNA segments. This assists in constructing family trees, confirming relationships, and uncovering migration patterns. Genetic testing companies such as MyHeritage DNA analyze specific markers to determine relatedness and provide ethnicity estimates. Though powerful, DNA testing's accuracy depends on databases' size, diverse representation, and the depth of ancestral information, enhancing our understanding of genealogical connections.
Genetic mutations and human health
Numerous genetic illnesses and diseases can be influenced by genetic mutations. There are specific gene mutations that constitute the root cause of diseases such cystic fibrosis, sickle cell disease, muscular dystrophy, and several cancers.[12] Researchers and medical professionals can develop more efficient treatments and therapies by better comprehending these alterations.
Explore more about genetic mutations
- The MyHeritage DNA test
- DNA Basics, Chapter 5: How DNA Testing Works from the MyHeritage Blog
- 5 Traits You Never Knew Were Hereditary from the MyHeritage Blog
- The Science Behind MyHeritage DNA Testing, webinar with Gal Zrihen on the MyHeritage Knowledge Base
References
- ↑ Sevilla, M. D., Becker, D., Yan, M., & Summerfield, S. R. (1991). Relative abundances of primary ion radicals in. gamma.-irradiated DNA: cytosine vs. thymine anions and guanine vs. adenine cations. The Journal of Physical Chemistry, 95(8), 3409-3415.
- ↑ Valenzuela, P., Gray, P., Quiroga, M., Zaldivar, J., Goodman, H. M., & Rutter, W. J. (1979). Nucleotide sequence of the gene coding for the major protein of hepatitis B virus surface antigen. Nature, 280(5725), 815-819
- ↑ Botstein, D., & Risch, N. (2003). Discovering genotypes underlying human phenotypes: past successes for mendelian disease, future approaches for complex disease. Nature genetics, 33(3), 228-237.
- ↑ Moore, J. H. (2003). The ubiquitous nature of epistasis in determining susceptibility to common human diseases. Human heredity, 56(1-3), 73-82.
- ↑ Loeb, K. R., & Loeb, L. A. (2000). Significance of multiple mutations in cancer. Carcinogenesis, 21(3), 379-385.
- ↑ Pisoschi, A. M., & Pop, A. (2015). The role of antioxidants in the chemistry of oxidative stress: A review. European journal of medicinal chemistry, 97, 55-74.
- ↑ Nollau, P., Wagener, C., & Division, O. B. O. T. I. S. (1997). Methods for detection of point mutations: performance and quality assessment. Clinical chemistry, 43(7), 1114-1128.
- ↑ Evans, H. J. (1982). Chromosomal mutations in human populations. Cytogenetic and Genome Research, 33(1-2), 48-56.
- ↑ Ripley, L. S. (1990). Frameshift mutation: determinants of specificity. Annual review of genetics, 24(1), 189-211
- ↑ Dingli, D., Pacheco, J.M. Stochastic dynamics and the evolution of mutations in stem cells. BMC Biol 9, 41 (2011).
- ↑ Bertram JS (December 2000). The molecular biology of cancer. Molecular Aspects of Medicine. 21 (6): 167–223
- ↑ Antonarakis, S. E., & Beckmann, J. S. (2006). Mendelian disorders deserve more attention. Nature Reviews Genetics, 7(4), 277-282