Genetic alphabet

Buccal swab is the collection of biomaterial from the inner surface of the cheek with a cotton pad. A swab allows you to painlessly obtain a sample of cells from the oral mucosa for subsequent genetic analysis.

A gene (from the Greek genos – genus, origin) is an elementary unit of heredity. A gene is a section of a chromosome that is responsible for a single trait, such as eye color or the amount of insulin produced.

A genotype is a set of genes, i.e. a set of traits that make up a person's individuality.

The genetic code is a system of encrypting hereditary information by means of uniquely sequential arrangement of four nucleic acid molecules. Imagine beads consisting of only four beads: there is no limit to the number and sequence of beads. For example, a gene that affects human height produces a protein molecule that consists of several hundred four nucleic acids arranged in succession. This unique protein sequence determines a person's future height.

Genetic testing, genetic test or DNA test is the analysis of  DNA molecule using sophisticated technical means. It is used to diagnose genetic diseases and predisposition to various pathologies. DNA test examines both individual genes and the entire set of chromosomes.

Deoxyribonucleic acid (DNA) is a huge ("macro-") molecule in the cell nucleus that is made up of many unique genes. DNA damage (e.g., irradiation of germ cells, from which the fetus subsequently forms) leads to genetic mutations

Sequencing - the determination of the sequence of nucleic acids in a gene.

Genetic mutations is congenital defects of genes of varying severity: from a single gene to an entire chromosome. Thus, mutations can manifest themselves in a variety of diseases, the severity of which depends on the number of mutated genes or entire chromosomes. Milk intolerance (lactase deficiency) is an example of a mutation in a single gene that encodes only one trait: an enzyme that processes milk. Down syndrome is an example of a mutation at the level of entire chromosomes. Mutations involve changing gene fragments, doubling them or removing them completely.

Chromosome are two strands of DNA crossed in the middle form an X-shaped chromosome. Normally, each human cell (with the exception of egg cells and spermatozoon) has 23 pairs of chromomas, with one pair represented by set of XY or XX chromosomes, where X is chromosome responsible for female development of the body, Y is for male development. In males, the set of chromosomes is designated as 23 XY, in females are 23 XX.

Hot spot sequencing is a research method aimed at detecting a hot spot mutation in a gene to diagnose diseases associated with a defect in a single gene. As you know, a mutation does not change the entire structure of a gene, but only a small part of it. The advantage of the method is the low price, the disadvantage is the probability of "making a mistake" in the defect search area, since the "hot spot" may differ for different ethnic groups. In the absence of reliable information about the points of gene damage in a particular geographical region, the use of another method is full gene sequencing is recommended.

Full gene sequencing is a method of genetic research that determines the sequence of nucleic acids in an entire gene. Despite its high cost, this method is preferred for diagnosing genetic diseases in regions where there is no information about point genetic damage. Kazakhstan is one of them.

Exone sequencing is a method of genetic testing that allows you to detect the presence of a mutation in a patient that may have been passed on from parents. In this case, the presence of the mutation must be confirmed in one of the patient's parents. Most often, analysis are prescribed to children to find out whether hereditary diseases identified in their parents have been passed on to them.

Deletions and duplications ("removals and doublings") - Deletions and duplications are variants of gene mutations in which there is not a change in a gene fragment, but a removal or duplication of this section. This method is prescribed in the case of negative sequencing, if the patient has a clinical picture of the desired disease. This is due to the fact that in rare cases, in spite of the classical mutation, a deletion or duplication of a fragment may occur. Another reason for the appointment is that there is evidence that most mutations in a particular gene are associated with deletions or duplications, rather than point mutations.

NGS-panel (Next-Generation Sequencing-panel) is a screening method of genetic diagnosis that allows you to identify a predisposition or disease that is characterized by the presence of mutations in different genes. For example, an oncology panel that detects a predisposition to colorectal cancer (rectal cancer).

A sibling test is a genetic test that allows you to establish a blood relationship between the person being tested and his or her supposed brother or sister.