A Few Words about Modern Genetics

Abstract

The human organism is composed of cells that have their own building blocks, among which the most important role is played by the nucleus, which contains the genetic material that we inherit from our parents, and which carries information about the way the human organism should function. This genetic material is found on DNA molecules, and DNA molecules are packaged in the form of chromosomes, which are formed by wrapping DNA molecules around proteins. Hereditary diseases are caused by mutations of one or more genes, which we inherited from one or both parents. Hereditary diseases are not the same as genetic diseases because some mutations and gene damage can occur after fertilization and later in a person’s life. Some genetic defects can be manifested by congenital malformations or diseases, but the defects of some genes will lead to disease symptoms only in adulthood or only under the influence of environmental factors. Through research in the field of molecular biology, the method of analyzing genetic markers is continuously improved, the sensitivity threshold of the method is lowered, and thus the analysis of increasingly scarce biological samples is enabled. The ultimate goal of biological expertise is to establish the identity of the person from whom the disputed trace originates, and for this purpose, the DNA profile of the disputed trace is compared with the DNA profile of an undisputed sample of the person. Non-disputable samples are blood samples or samples of oral cavity epithelium that are taken from a person of known identity. The match of the DNA profile of the disputed trace with the DNA profile of the undisputed sample confirms that the disputed trace originates from a certain person.