Did you know that all human beings share 99.9% of genetic information? This means that what makes us unique depends only on that remaining 0.1%. Any change in the DNA sequence can alter the genetic code and, therefore, may alter the synthesis of the protein it codes for. Find out more about Eurofins sequencing here.
Therefore, the clinical implication of a genetic alteration will depend on where it occurs. That is if it takes place in the coding region or not. Also, if the alteration causes a drastic change in the synthesis of the protein and therefore in the function that it carries out in the body.
What Kinds of Changes Can There Be?
The various types of genetic alterations include:
- Substitution: Change from one base to another.
- Deletion: Elimination of a series of bases.
- Duplication: Duplication of a fragment of bases.
- Inversion: Inversion of the order of a sequence of bases.
Why Do Genetic Alterations Occur?
We can say that, in general, genetic alterations have two origins:
- Due to external factors, of an environmental nature.
- Due to internal factors, of a genetic nature.
The human body regularly renews almost all the cells in its body, for this the cells divide, giving rise to two daughter cells. During this division process, errors can occur that lead to the formation of genetic alterations.
External factors such as tobacco or solar radiation, among many others, increase the probability that these types of errors will take place. These genetic alterations that affect only the cell in which the error has occurred, are called somatic and are not transmitted to the offspring.
However, genetic alterations can also be present from birth. If the egg or sperm has an error in its genetic material, it will be transmitted to the zygote and will remain present in all its cells. It is also possible that the alteration occurs during embryogenesis (the process of transformation from the zygote to the embryo) although the sex cells do not present it. In both cases, these alterations are called germ, and the people who present them can transmit them to their offspring.
Genetic Alterations: Mutations and Polymorphisms
You’ve probably heard of mutations, and in all likelihood, you associate the term with something negative. Mutations are genetic alterations that occur in less than 1% of the population and that are associated with a higher risk of developing a disease.
Polymorphisms are genetic alterations that are present in more than 1% of the population. Most of the polymorphisms are known as single nucleotide polymorphism.
SNPs are responsible for 90% of what differentiates us from each other, that is, they determine most of the genetic variability between individuals.
Genetic Variation, Key in Evolution
Genetic variations that we all have are what make us unique. If there were no genetic variation, there would be no evolution. The origin of all genetic variation is mutations, that is, stable and heritable changes, in successive generations, in the genetic material.
Each species has a different mutation rate, modulated by natural selection so that it can face in a balanced way the double situation of stability-change, inherent in every environment.
What Defines You Genetically?
At the beginning of the 21st century, the first draft of the human genome sequence was published. Thanks to the participation of international institutions, it was possible to carry out the Human Genome Project, which was developed between 1990 and 2003.
These scientific advances began the genomic era in the field of biology and medicine and made it possible to establish the sequence of the reference human genome.
Now you know why people have different physical features. It all depends on that 0.1% that makes us unique. The ability to detect these genetic alterations in a preventive way is essential to be able to adapt our way of life to our genetics and improve our quality of life.