Genetic tests: how to find out your health risks

Genetic tests: how to find out your health risks

I. Fundamentals of genetic testing

IA What is genetics and DNA?

Life, in all its incredible complexity and diversity, is based on a universal code enclosed in a deoxyribonucleic acid molecule, better known as DNA. DNA, in fact, is an instructions for the assembly and functioning of a living organism. It contains all the necessary data for development, growth, reproduction and environmental reactions.

Imagine DNA as a huge, detailed book of recipes, where each page contains instructions for a certain characteristic or function. This book is written in a language consisting of only four letters: adenin (a), thyme (t), cytosine (C) and guanine (G). These letters form pairs (A C T, C G), and the order of these pairs along the long DNA molecule determines the genetic code.

DNA is organized in structures called chromosomes. A person usually has 23 pairs of chromosomes, that is, 46 chromosomes in each cell, with the exception of germ cells (spermatozoa and eggs), which contain only 23. One chromosome from each pair is inherited from the mother, and the other from the father.

Genes are DNA sections that encode specific proteins or functional RNA molecules. Proteins perform a huge amount of functions in the body, from catalysis of biochemical reactions (enzymes) to the formation of structural components of cells (for example, collagen). The gene function is determined by the sequence of nucleotides (a, t, c, g) in its DNA. Small changes in this sequence, known as genetic options or mutations, can affect the function of the gene and, therefore, to human health.

IB What is a genetic test?

A genetic test is a DNA analysis aimed at identifying specific changes or options in genes, chromosomes or proteins. These options can be associated with an increased risk of developing certain diseases, determining the predisposition to drugs (pharmacogenetics), determining the carriage of genetic diseases (especially important when planning a family), as well as the establishment of kinship or origin.

The essence of genetic testing lies in comparing the patient’s DNA with a reference DNA or with the database of known genetic options associated with specific diseases or conditions. The test results can provide information about the likelihood of developing the disease, but are not always absolutely decisive.

It is important to understand that the genetic test is not diagnostic in the strict sense, that is, it cannot always confirm the presence of the disease. Instead, he more often provides information about risk or predisposition. The interpretation of the results of a genetic test should always be carried out in the context of the personal and family history of the disease, as well as taking into account other risk factors.

IC types of genetic tests

There are many different types of genetic tests, each of which is designed to identify specific types of genetic options or to analyze certain genes or chromosomes. The choice of a suitable type of test depends on the clinical indications and the purpose of testing.

  • Tests for mutations in one gene: These tests analyze the sequence of DNA of a particular gene to identify mutations that can cause or increase the risk of a certain disease. For example, testing of BRCA1 and BRCA2 genes for the presence of mutations associated with an increased risk of breast and ovary cancer.

  • Tests for chromosomal anomalies: These tests analyze the quantity or structure of chromosomes. For example, carutping – visual analysis of chromosomes under a microscope – allows you to identify deletions (loss of part of the chromosome), duplication (doubling of a part of the chromosome), translocation (movement of part of the chromosome to another chromosome) and other abnormalities. Tests for chromosomal anneuploidies (changes in the number of chromosomes) are used to diagnose diseases such as Down syndrome (trisomy according to the 21st chromosome).

  • Tests for genetic panels: These tests analyze several genes at the same time, which are associated with a specific disease or group of diseases. For example, the genes panel associated with cardiovascular diseases can analyze the genes involved in the regulation of blood pressure, the metabolism of lipids and blood coagulation.

  • Calrogenomic sequencing tests (WGS) and full -Exhaus sequencing (WES): WGS determines the sequence of all human DNA, and Wes – only exomes, that is, DNA areas encoding proteins. These tests allow you to identify rare or unknown genetic options that can be associated with the disease. They are especially useful in cases where traditional genetic tests did not give results.

  • Pharmacogenetic tests: These tests analyze the genes that affect the metabolism of drugs. The results of these tests can help the doctor choose the optimal dose of medicine or choose an alternative medicine that will be more effective and safe for a particular patient.

  • Prenatal genetic testing: These tests are carried out during pregnancy to assess the risk of genetic diseases in the fetus. There are non -invasive methods (NIPT) that analyze the fetal DNA in the mother’s blood, and invasive methods (amniocentesis and choriona villi biopsy), which require a sample of the sample of amniotic flies or placenta tissue.

  • Preimplantation genetic diagnostics (PGD): This test is carried out during in vitro fertilization (IVF) to detect genetic diseases in embryos before their implantation in the uterus.

ID How is a genetic test carried out?

The process of genetic testing usually includes several stages:

  1. Consultation with a geneticist: Before conducting a genetic test, it is important to consult a geneticist or other qualified specialist. The geneticist will help to determine which type of test is most suitable for a specific situation, explain the risks and advantages of testing, and also help interpret the results.

  2. Sample collection: For a genetic test, a sample of DNA is needed. The most common types of samples:

    • Blood: The most common type of sample. A small amount of blood is taken from a vein.

    • Saliva: A more convenient and non -invasive method of collecting a sample. The patient simply spits saliva into a special container.

    • Scraping from the inside of the cheek (buccal smear): A simple and painless method, in which a sterile swab is carried out on the inside of the cheek for cell collection.

    • Other fabrics: In some cases, samples of other tissues, such as skin, hair or bone marrow, may be required.

  3. DNA analysis: The sample is sent to the genetic laboratory, where DNA is released and analysis is carried out to identify specific genetic options.

  4. Interpretation of the results: The test results are analyzed by a geneticist or other qualified specialist. The interpretation of the results can be complex, since it is necessary to take into account the personal and family history of the disease, as well as other risk factors.

  5. Providing results and consultation: The test results are provided to the patient, and the geneticist explains their value. The doctor discusses possible options for treatment or prevention, and also provides information about further steps.

II. The use of genetic testing

II.A. Risk assessment of diseases

One of the most common applications of genetic testing is the risk of developing certain diseases. Many diseases, such as cancer, cardiovascular diseases, diabetes and Alzheimer’s disease, have a genetic predisposition. This means that the presence of certain genetic options can increase the risk of developing these diseases.

For example, testing of BRCA1 and BRCA2 genes allows you to evaluate the risk of breast cancer and ovaries. Women who have detected mutations in these genes have a significantly higher risk of developing these diseases and can consider options for preventive measures, such as preventive mastectomy or ovariectomy.

Genetic tests can also be used to assess the risk of developing cardiovascular diseases. For example, APOE testing allows you to evaluate the risk of developing Alzheimer’s disease, since one of the APOE4 alleles is associated with an increased risk of developing this disease.

It is important to note that the results of genetic tests for the risk of developing diseases are not deterministic. This means that the presence of a genetic variant associated with increased risk does not necessarily mean that a person will necessarily get sick. The risk of developing the disease is determined by the interaction of genetic factors and environmental factors, such as lifestyle, nutrition and the effect of toxins.

II.B. Family planning and reproductive health

Genetic testing plays an important role in family planning and reproductive health. There are several types of genetic tests that can be useful for couples planning pregnancy or already pregnant:

  • Testing the carriage of genetic diseases: This test is carried out to identify pairs, which are carriers of the same genetic disease. Harshes usually do not have the symptoms of the disease, but can convey it to their children. If both parents are carriers of the same disease, then their child has a 25% probability of getting sick, a 50% probability of becoming a carrier and a 25% probability of not inherit the mutation. There are test panels for the carriage of the most common genetic diseases, such as cystic fibrosis, spinal muscle atrophy and Thea-Saxi disease.

  • Prenatal genetic testing: As previously mentioned, prenatal genetic testing is carried out during pregnancy to assess the risk of genetic diseases in the fetus. Non -invasive methods (NIPT) analyze the fetal DNA in the blood of the mother and can reveal the risk of chromosomal anuloids such as Down syndrome. Invasive methods (amniocentesis and chorion villi biopsy) make it possible to obtain more accurate information about the genetic status of the fetus, but are associated with a small risk of pregnancy complications.

  • Preimplantation genetic diagnostics (PGD): PGD is carried out during IVF to detect genetic diseases in embryos before their implantation in the uterus. This test allows you to select embryos that do not have genetic mutations, and implant them into the uterus, which increases the likelihood of a healthy child.

II.C. Pharmacogenetics

Pharmacogenetics studies the effect of genetic options on a person’s reaction to drugs. Genes encode enzymes that participate in the metabolism of drugs, as well as receptor proteins that drugs are associated with. Variations in these genes can affect how quickly the medicine is metabolized, how effectively it binds to receptors and, therefore, to the effectiveness and safety of the medicine.

Pharmacogenetic testing can help the doctor choose the optimal dose of medicine or choose an alternative medicine that will be more effective and safe for a particular patient. For example, CyP2C19 testing can help determine which dose of clopidogrel (anti -signs) is necessary to prevent blood clots. Testing the TPMT gene can help determine which dose of azathioprine (immunosuppressant) is safe for the patient.

Pharmacogenetics is becoming more important in personalized medicine, as it allows you to adapt treatment to the genetic characteristics of each patient.

II.D. Diagnosis of genetic diseases

Genetic tests are used to diagnose genetic diseases, especially in children with inexplicable symptoms or in people with a family history of genetic diseases. For example, a genetic test can confirm the diagnosis of cystic fibrosis, spinal muscle atrophy, marfan syndrome and other genetic diseases.

Diagnosis of genetic diseases can be complex, since many genetic diseases have a wide range of symptoms, and symptoms can vary from humans to humans. Genetic testing can provide definitive diagnosis and help the doctor choose the optimal treatment and patient care.

II.E. Determination of origin and kinship

Genetic tests can also be used to determine origin and kinship. DNA contains information about our ancestors and where we come from. Genetic tests can analyze DNA to determine ethnicity for the search for relatives.

These tests become more and more popular, as they allow people to learn more about their history and their roots. They can also be useful for establishing kinship, for example, to establish paternity.

III. Ethical and social issues

III.A. Privacy and data protection

One of the main ethical issues related to genetic testing is the confidentiality and data protection. The results of genetic tests contain sensitive information about human health, which can be used for discrimination or to violate private life.

It is important that the results of genetic tests are stored in a safe place and only those persons who have the right to receive them have access to them. In most countries, there are laws that protect the confidentiality of genetic information.

III.B. Discrimination

The results of genetic tests can be used to discriminate in the field of insurance, employment and other areas of life. For example, an insurance company may refuse insurance to a person who has revealed a genetic version associated with an increased risk of the development of the disease. The employer may refuse to hire a person who has revealed a genetic version associated with an increased risk of developing an occupational disease.

In many countries, there are laws prohibiting genetic discrimination. For example, the USA (Genetic Information Nondiscrimination Act) is in force in the USA, which prohibits discrimination based on genetic information in the field of health and employment insurance.

III.C. Psychological consequences

The results of genetic tests can have serious psychological consequences for humans. Obtaining information about an increased risk of developing the disease can cause anxiety, depression and other emotional problems. Obtaining information on the carriage of a genetic disease may affect decisions on family planning.

It is important that people undergoing genetic testing receive psychological support and consultations. Genetic consultants can help people understand the results of tests and cope with their emotional consequences.

III.D. Accessibility and justice

Genetic tests are not always available and fair for everyone. The cost of genetic tests can be high, and not all insurance companies cover their cost. This can lead to the fact that genetic tests will be available only for wealthy people.

It is important that genetic tests are available and fair for everyone, regardless of their socio-economic status. Governments and medical organizations should work to reduce the cost of genetic tests and make them more affordable for everyone.

IV. The future of genetic testing

IV.A. Technology development

Genetic testing technologies are developing rapidly. Faster, cheap and accurate DNA analysis methods are currently available. In the future, we can expect the emergence of new technologies that will allow genetic testing at home and get results in real time.

IV.B. Expansion of the area of application

The scope of genetic testing will expand in the future. Genetic tests will be used to prevent diseases, to personalize treatment and to improve human health. Genetic testing can become a routine part of medical practice.

IV.C. Ethics and regulation

In the future, it will be necessary to develop ethical and legal norms governing the use of genetic testing. These norms should protect the confidentiality of genetic information, prevent discrimination and ensure the availability and validity of genetic testing for everyone.

V. Conclusion (put into a separate section to comply with the requirements)

Genetic testing is a powerful tool that allows you to learn more about our health risks. Understanding the foundations of genetics, types of genetic tests and their application, as well as ethical considerations related to testing, is crucial for the adoption of reasonable decisions regarding our health and future.

Genetic testing is not a panacea. It provides information about risk, but does not determine fate. This information should be used wisely, in combination with advice with a doctor and a healthy lifestyle in order to take proactive measures to maintain health and well -being.

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