## Genetics or epigenetics - which is more?

The fundamental discoveries brought about by epigenetics have shaken the classical understanding of genetics. Until now, it has been generally accepted that not only our appearance, but also to a certain extent our behaviour, intelligence and predisposition to diseases are dependent on the genes we have inherited. The study of epigenetics has shown that the statement “our destiny is written in genes“ needs to be changed. It seems that we can influence our genetic inheritance to some extent and this influence can be passed onto future generations. Epigenetic changes are thus necessary for the proper development and functioning of the organism, but they can also be responsible for the development of many diseases. Disruption of the proper function of epigenetic mechanisms can mean abnormal activation or silencing of genes. In humans, epigenetic changes can cause the development of cancer, but also schizophrenia and autism. Although epigenetic changes are heritable, unlike genetic ones, they are also reversible – so there is a possibility to reverse such modifications and thereby restore the normal state in the cell.

According to the current idea, the DNA of an organism serves as a universal building plan, but at the same time, a different set of genes is expressed in each type of cell, so that different parts of this plan are implemented in different places in the body. The differences in the expression of individual genes are also regulated by epigenetic modifications, so it is necessary to take into account that each of the many different types of cells has its own epigenome. Currently, as part of the Human Epigenome Project, scientists are trying to identify all the chemical changes and relationships that mediate the realization of the genetic information stored in DNA. Thanks to this information, in the future it will be possible to better understand processes such as natural development, aging, carcinogenesis and the development of other diseases, as well as the impact of environmental factors on human health. So if we were to think of the human genome sequence as a map, the goal of the human epigenome will be to find out which pathways are open and which are closed.