Genetic material is passed from one generation to another and assures that the next generation of species is a precise copy of their parents. This mechanism is common to all living beings including humans. Genetic material conveys all kinds of information about ourselves, including our appearance, habits, and even diseases. Therefore, genetic information sufficiently influences our health. Both physical and mental conditions can be inherited, and people can never be sure about their safety if their relatives had genetic diseases. Due to recombination of genes, there is only a chance that either of the family diseases is inherited by future generations. The only way to reveal “wrong” genes is to make a test.
Genetic diseases emerge because some copies of genes undergo mutations. In fact, very few mutations impair functioning of the body. Some mutations work better than original genes, the others do not cause any change at all. But few badly mutated genes may cause serious disorders. Mutations are frequently a cause of such widespread diseases as cancer or diabetes or of rare conditions as Parkinson’s or Crohn’s disease.
Another peculiarity of genetic material is that it can be inherited in a different amount. It is called a copy number variation. This phenomenon explains why instead of two copies of a gene inherited from each parent a child may inherit one, or three, or multiple genes. Sometimes, a pair of genes may be entirely missing which is another reason for developing conditions. The same refers to chromosomes that are groups of genes. Missing chromosomes may cause severe deviations in the functioning of a human body.