With scientific and technological developments, more information is gained about our body and its building blocks, which we call the cell. The identified biological mechanisms and molecules enable the development of new treatment methods for health problems, while paving the way for new applications both in medical science and in other areas of life. A significant part of these technological developments are experienced in the field of genetics. Today, one of the methods defined and widely used thanks to the possibilities in genetics is DNA testing.
What is DNA Testing?
Deoxyribonucleic acid, or DNA for short, is the biological structures that make up our genetic code, located inside our cells, the building blocks that make up our body, and in which all our features are encoded. The codes created by certain combinations of the building blocks called nucleic acids that make up DNA are called genes. Genes; These are personal codes that determine all the characteristics of the body, such as eye color, height, hair style, or susceptibility to heart disease. With the influence of the environmental factors we are exposed to, our personal characteristics are shaped and our body continues to live accordingly.
Thanks to the genetic methods developed today, genes and DNA molecules that make up genes can be examined in detail and the genetic codes that make up personality traits can be revealed. In this way, in addition to personal biological identity features such as fingerprints, the identity of individuals can be verified, the presence of certain health problems can be investigated or the risk of people suffering from ailments can be determined. DNA tests are widely used in the clinic, especially in the diagnosis of genetically based diseases.
Why is DNA Test Done?
Our genes encode health features as well as all features of the body. In other words, from the activity of the immune system to the vascular structures, from the durability of the skin to the brain functions, the features that concern biological health develop through genes. Various health problems may occur as a result of some genes being damaged or faulty due to factors that cause changes in the genetic sequence, such as congenital causes or subsequent mutations. In this group of diseases, also known as genetic diseases, changes and disorders may develop in a certain part of the body or in the whole.
Although it is important to evaluate the clinical signs and symptoms as a whole when diagnosing genetic diseases, definitive diagnosis depends on the detection of the problematic gene in the DNA sequence. Thanks to DNA testing, problems or deficiencies in the genetic sequence can be detected. In this way, the correct treatment and management of diseases detected in children at an early age or in the womb can be provided, and thus, counseling services can be provided to parents for subsequent pregnancies.
Individuals whose genetic sequences are found to contain genes that can cause disease are defined as genetic carriers. When carriers have children with people with similar genes, the probability of having children with a genetic disease increases. For this reason, genetic counseling can be provided to people who were determined to be carriers before DNA tests, and they can be informed about the risk of having a child with genetic diseases, or a risk assessment can be applied to couples by performing genetic screening tests before marriage. Alternative childbearing methods, which may be safer in terms of genetic diseases such as in vitro fertilization, may be recommended for individuals at risk.
In addition, DNA testing can be used to determine the relationship or heredity of the biological sample obtained in forensic cases with a certain identity. Genetic sequences belonging to the mother and father are passed on to the next generations. As a result of combinations of certain genes from the mother and father; Children with similar genes are born with a completely unique and independent new genetic sequence. Thanks to DNA testing, in forensic cases, it can be determined which biological material belongs to the people who have been sampled before, or it can provide valuable data when it is necessary to determine the relationship between the parent and the child.
Genetic tests can also provide important data in the preparation of the treatment plan for some diseases. Since cancer is a health problem that arises mainly due to genetic reasons, by performing gene analyzes of cancer tissues obtained from patients, substances that can be targeted in cancer treatment can be detected and targeted smart drug treatments can be applied. Again, genetic analyzes can provide important information about the severity of the cancer in patients, possible complications and cancer subtypes.
How is DNA Test Done?
In DNA test; specific targeted gene sequences, It is determined whether it is present in the DNA sequence of the local. In this sense, important information about the diagnosis of the disease can be obtained by examining the genetic sequences determined by scientific studies to be associated with a specific disease. The DNA of the cells included in the material investigated in the DNA test is purified by special methods. Then, gene-producing enzymes are used to make copies of a particular gene in the DNA sample, which is made suitable for sequencing with enzymes and chemicals. Enzymes produce copies that are exactly matched to the gene under investigation, and the duplicates are detected through various steps.
If the targeted gene is not located in the DNA, the said copies cannot be detected, and thus an interpretation can be made in terms of the absence of the gene in the patient or the change in its structure as a result of mutation. With the help of various devices, the DNA sequence of the targeted genes can also be revealed. As a result, in the light of all these studies, a detailed examination can be made about the presence or absence of the targeted gene, whether it is mutated and its sequencing in the researched material.
Genetic testing can be done on a small scale only on a specific gene, or it can be done on a large scale along large genetic structures called chromosomes. In diseases such as Down syndrome and Turner syndrome with changes in the number of chromosomes, or in leukemia in which the chromosome structure has changed, chromosome analysis can give very important data in terms of diagnosis and treatment. Thanks to scientific researches, it is predicted that the number and effectiveness of treatment methods at the gene level will increase in the near future. With these treatment methods, also known as gene therapy, it is expected that genetic diseases can be treated and more effective treatment practices will be implemented in genetic-based health problems. Evaluation of patients before gene therapies will be possible with the mentioned DNA tests.