Genetic analysis is gradually becoming a popular study. With the help of this type of laboratory research, doctors can establish not only the degree of kinship, but also the predisposition to a particular disease. Let's consider in detail the analysis, we will tell about its kinds and features of carrying out.
Methods of genetic analysis
Genetic examination - a large set of laboratory studies, experiments, observations and calculations. The main purpose of such measures is to determine hereditary traits, study the properties of individual genes. Depending on the purpose of this or that analysis, the following types of examination are distinguished in medical genetics:
- analysis of DNA structure;
- chromosome analysis;
- genetic compatibility analysis;
- research on the predisposition to diseases.
DNA analysis
Carrying out such a study as DNA analysis for paternity helps to establish the biological parent of the child with a large percentage. For his conduct, the material is taken from the mother, the baby and the alleged father. As an object of research can act saliva, blood. Quite often a buccal scraping is carried out (picking up the material from the inner surface of the cheek).
With the help of a special device, when genetic analysis is carried out, certain fragments in a DNA molecule that carry genetic information - loci are revealed. Under a multiple increase, the lab evaluates 3 samples at once. Initially, the genetic material that the child inherited from his mother is singled out, then the remaining plots are compared with those in the sample of the alleged father. Directly, genetic analysis is carried out for paternity.
Chromosomal analysis
Analysis of chromosomal pathology helps to establish the presence of possible diseases in an unborn baby. To do this, doctors use prenatal screening. It includes blood sampling for research and ultrasound. The interpretation of the results is carried out exclusively by the doctor. At the same time, a definitive diagnosis is not made on the basis of one screening. Bad results are an indication for further examinations. The discrepancy between the values of the norms may be a sign of the presence of such chromosomal abnormalities as:
- Down syndrome ;
- trisomy 13 and 18 chromosomes;
- Turner syndrome;
- Klinefelter's syndrome.
Genetic tests in pregnancy planning
Analysis for genetic compatibility establishes the possibility of conceiving a child from a particular partner. In practice, it often turns out that many married couples can not have children for a long time. At the reference to doctors, among obligatory researches - the analysis on genetic compatibility. It is conducted in the conditions of large clinics and in family planning centers.
The cells of the human body have on their surface a specific protein HLA - human leukocyte antigen. It was possible to establish more than 800 species of this protein. Its function in the body is the timely recognition of viruses, pathogens. When an alien structure is detected, they send a signal to the immune system, which starts production of immunoglobulins. If the system is malfunctioning, this reaction also occurs on the embryo that forms, which leads to spontaneous abortion.
In order to exclude the development of this situation, physicians recommend passing the genetic analysis for compatibility. When it is conducted, protein structures of partners are evaluated, their similarity is compared. It is worth noting that incompatibility is not in fact an obstacle to pregnancy. After conception, a woman is taken into control, carrying out prophylaxis of interruption of gestation, when she is pregnant in the hospital.
Genetic analysis during pregnancy
Such a study as a genetic analysis of the fetus makes it possible to diagnose chromosomal pathologies in the early stages of a child's development within the mother's womb. Such a study is often called screening. Its composition includes not only an analysis of the genetic material of the baby, but also an examination of the future baby with the help of ultrasound. So doctors can identify violations that are incompatible with life, vices. The very same study aims to eliminate genetic abnormalities, helps to establish the probability of development, by estimating the concentration in the blood of compounds such as:
- HCG ;
- AFP ;
- APP-A.
Often such indicators doctors use, as markers - if their values do not meet the established standards, physicians prescribe a further examination. As such, invasive methods are used. Their use is associated with a risk of complications of pregnancy. Because of this, the appointment is conducted in rare cases. These types of analyzes include:
- biopsy of the chorion - analysis of the tissue particles of the outer envelopes of the embryo;
- blood sampling from the umbilical cord;
- analysis of amniotic fluid.
Genetic analysis for susceptibility to diseases
An analysis of genetic diseases helps to assess with a high degree of accuracy the risks of developing a pathology in a born baby. The material is taken in a hospital, on the 4th day, if the baby has appeared on time, and a week later in premature babies. Blood sampling is carried out from the heel. Several of its drops are immediately applied to a special test strip, and then sent to the laboratory. In this genetic analysis, physicians establish a tendency to such pathologies as (genetic full analysis):
- Cystic fibrosis. Disease of a hereditary nature, in which the work of the respiratory and digestive systems is disrupted.
- Phenylketonuria. With such a disease, the structures of the brain undergo changes - neurological disorders develop, mental retardation is formed.
- Congenital hypothyroidism. The disease develops because of an inborn deficiency of thyroid hormones. This process inhibits the physical and mental development of the baby. Hormonotherapy is the only way to treat it.
- Galactosemia. Violation of the functioning of internal organs (liver, nervous system). The child is forced to observe a dairy-free diet, undergo special therapy.
- Adrenogenital syndrome. Formed with increasing synthesis of androgens.
Genetic analysis of oncology
In the course of numerous studies of the nature of the oncological process, scientists managed to establish the relationship of the disease with the hereditary factor. There is a so-called genetic predisposition to oncological diseases - the presence in the genus of ancestors that were susceptible to impairment, significantly increases the risk of development of oncology in offspring. For example, geneticists have determined that BRCA1 and BRCA2 genes are responsible for the development of breast cancer in 50% of cases. Genetic predisposition to cancer is caused by a mutation of these genes.
Genetic analysis for obesity
For several decades, nutritionists have conducted numerous studies, trying to establish the cause of excessive weight. As a result, it was found that, in addition to malnutrition, an unbalanced diet, there is also a genetic predisposition to obesity. So from an early age, it is possible to trace the relationship between the body mass index and the predisposition to weight gain. The peak is at the time of hormonal changes in the body - the period of puberty, pregnancy and breastfeeding, menopause.
Among the genes responsible for weight gain, genetics are called:
- FTO - responsible for weight;
- HMGI-C - activates the growth of fat cells;
- NRXN3 - affects the formation of a feeling of saturation;
- FIT1 and FIT2 - stimulate the formation of adipocytes - the cells from which the fat tissue is formed.
When assessing the condition of organs and systems, to determine the predisposition to obesity, a genetic analysis of the blood is performed to determine the concentration of such substances as:
- leptin - regulates metabolic processes in the body, increasing energy expenditure;
- T4 free, TSH - thyroid hormones;
- glycated hemoglobin, glucose - characterize the state of carbohydrate metabolism.
Examination for genetic thrombophilia
Increased propensity to form blood clots, thrombi, is determined at the level of heredity. Genetic predisposition to thrombophilia is noted when a mutation occurs in the gene, which is responsible for the blood clotting factor - F5. This leads to an increase in the rate of thrombin formation, which enhances the processes of blood clotting. The mutation in the prothrombin gene (F2) increases the synthesis of this factor in the coagulation system. In the presence of such mutations, the risk of thrombosis increases several times.
Genetic examination for lactase insufficiency
Lactose intolerance is a violation, which fixes the body's inability to absorb milk sugar, due to a decrease in intestinal synthesis of the enzyme lactase. Often, in order to establish the disease and a predisposition to it, a genetic analysis is performed to determine the genes C / T-13910 and C / T-22018. They are directly responsible for the low synthesis of enzymes. Evaluation of their structure helps with establishing the possible development of impairment in descendants, carriers of these genes. Decoding of the genetic analysis is carried out by specialists.
Genetic examination for Gilbert's syndrome
Gilbert syndrome - congenital hepatic pathology, which refers to benign disorders. Often bears a family character, passes from parents to children. It is accompanied by an increase in the level of bilirubin. The reason lies in the violation of the synthesis of the enzyme glucuronyltransferase contained in the liver cells and takes part in the binding of free bilirubin. A genetic blood test helps to establish pathology by evaluating the UGT1 gene and its copy.
Genetic predisposition to alcoholism
The doctors studying the problem are conducting long studies, trying to establish a link between cravings for alcohol and genetics. However, a genetic predisposition to such a disease is not established. There are many hypotheses, but they have no concrete confirmation. Doctors themselves often talk about the disease as a acquired illness, a consequence of an independent choice. This is confirmed by successful, successful people whose parents suffered from alcoholism.
Genetic passport
Increasingly in health clinics among the services provided can be seen in the list such as a full genetic health passport. It involves a complete genetic analysis of the body, which aims to establish a predisposition to a particular group of diseases. In addition, the evaluation of the hotel genes helps to identify the propensity to a certain type of activity, to establish hidden talents.