To increase the birth rate and reduce the frequency of morbidity, disability and mortality of the population in the regional medical and genetic consultation (KMGC) service has been created
Molecular genetic diagnostics in family planning
To increase the birth rate and reduce the frequency of morbidity, disability and
Mortality of the population in the regional medical and genetic counseling (KMGC) service
Molecular genetic diagnosis, which allows you to identify hereditary diseases and polymorphisms in predisposition genes to complex diseases.
This type of diagnosis makes it possible to predict various diseases and pathological conditions of a person on the basis of a study of the individual characteristics of its genome. For many diseases, major genes have already been allocated, the products of which play a key role in the initiation of the pathological process. The number of such genes is very limited.
Predisposition genes are variants of genes compatible with normal livelihoods, but under adverse conditions or over time, they are a starting mechanism for developing diseases.
Testing polymorphisms of genes, we can find out what pathology and what probability is waiting for a patient in the future. Currently, genetic testing allows you to identify the trends in the genome to appear pathology, increased sensitivity of a person to those or other diseases, but it does not make a final diagnosis. Based on this information and modern medical experience, it is possible to outline the paths of early prevention and with the help of correction to weaken the adverse effects of functionally defective genes.
So, for example, the G1691A Leiden polymorphism (Leiden's mutation) increases the likelihood of the development of a number of complications of pregnancy: miscarriage in early terms (the risk increases 3 times), delay in the development of the fetal, late toxicosis (gestosis), fettlacementar insufficiency. The presence of a mutation increases the risk of primary and recurrent venous thrombosis, 3-6 times, and if the patient, in addition to mutation, Leiden's coagulation factor V also has a mutation T of polymorphism C677T gene of methyltetrahydropholate-hydrotases, the risk of venous thrombosis increases more than 8 times. One of the most dangerous complications of hormonal contraceptives are thrombosis and thromboembolism. Many women with such complications are heterozygous carriers of Leiden mutation (GEGODIP G / A). Against the background of receiving hormonal contraceptives, the risk of thrombosis is increased by 6-9 times. In women using hormonal contraceptives and having homozygous mutation, Leiden (A / A genotype), the risk of cerebral sinus thrombosis (TCS) is elevated more than 30 times compared with patients who do not have this mutation. Accordingly, it is necessary to plan the management of such patients only with information about the presence of this mutation.
Functionally defective variants of metabolism genes show a clear association with breast and ovarian cancer, various obstetric and gynecological diseases (infertility, endometriosis, antiphospholipid syndrome, recurrent miscarriage, preeclampsia, etc.), as well as with congenital malformations of the fetus: defects in the nervous system, anencephaly, deformation of the facial skeleton (cleft palate, cleft lip), prenatal death of the fetus.
Molecular genetic studies in family planning should be carried out in two stages.
The first is the examination of spouses directly during the initial treatment and the creation of a genetic map of reproductive health based on the data obtained. This map reflects the carriage of certain gene diseases and hereditary predisposition to the occurrence of multifactorial diseases. Based on data on hereditary predisposition (for example, to arterial hypertension, coronary artery disease, a tendency to thrombosis, oncological pathology), a plan for managing spouses, preventive measures, both before and after pregnancy, is built.
The second stage is intended for carriers of hereditary diseases who have a high risk of having a sick child. Women in such married couples undergo intrauterine molecular genetic diagnostics (starting from the 9th week of pregnancy – chorion biopsy, placentocentesis, cordocentesis), which allows obtaining data on the health of the unborn child.
How are molecular genetic studies carried out?
The material for genetic testing is venous blood taken on an empty stomach in a special test tube. In the laboratory, DNA is extracted from the blood, which is used to set up a polymerase chain reaction (PCR), which allows identifying the gene under study and detecting mutations in it. Since human cells contain a double set of all genes, the result of the conclusion contains information about the presence of the studied mutation in each of the paired genes. Thus, for each point, it is possible to obtain three options for the conclusion:
- -/- no mutation (normal variant of polymorphism);
- -/+ mutation in heterozygous form (in one of the paired genes);
- +/+ mutation in homozygous form (in both paired genes).
If this mutation is inherited in an autosomal dominant manner, then it manifests itself both in a homozygous and in a heterozygous form; mutations inherited in an autosomal recessive manner appear only in the homozygous form.
Interpretation of the results of molecular genetic studies
A geneticist analyzes the information received about the presence of certain mutations / polymorphisms and draws up a genetic conclusion.The magnitude of the risk of diseases associated with certain mutations/polymorphisms is assessed and recommendations are developed for the patient and the attending physician, containing a program of preventive, therapeutic and diagnostic measures aimed at minimizing the identified risks.
Performing a laboratory test and drawing up a conclusion takes 2-3 weeks. Genetic testing for a given list of mutations/polymorphisms is carried out only once. The result of the study does not change throughout life. It is recommended to have a genetic conclusion with you whenever you seek medical help.
If unfavorable mutations or variants of polymorphisms are not detected, this does not mean that the patient may not pay any attention to his health. Let's put it this way: it is easier for the owner of “good” genes to maintain health, but if a person exposes his body to constant extreme stress, then even the best enzymatic systems encoded by the best genes may not be able to cope with constant tests and may fail. It must be remembered that any, even the best mechanism, has limiting load limits and its own resource. But at the same time, if a person has a reasonable attitude to the benefits that "good" genes provide, he will undoubtedly have a greater potential for self-realization, will have more opportunities to achieve his goals.
If the carriage of recessive mutations associated with hereditary monogenic diseases is detected, such patients require a consultation with a geneticist in case of planning the birth of a child.
If "bad" variants of polymorphisms associated with the risk of multifactorial diseases are found, this is not an inevitability of the development of the disease. As a rule, we are talking only about an increase in the risk of certain diseases relative to the average population level. If appropriate measures are taken to reduce the impact of external adverse factors, then the magnitude of this risk will be minimal. It is important that a person should know not only about the risks to their health, but also about ways to reduce this risk.
Where are molecular genetic studies carried out?
You can take tests for genetic polymorphisms at the regional clinical center for specialized types of care,
located at the address, Vladivostok, st. Uborevich 30/37.
Blood sampling is carried out at the 8th floor. in office 809, every day, except Saturday and Sunday, 9-15 a.m.
Tel. registries: (423) 242-84-57.
You can also book an appointment with a geneticist here.
Currently, it is possible to conduct studies of hereditary predisposition to:
If you have any questions about the molecular genetic examination, you can contact the head of the regional medical genetic consultation Voronin Sergey Vladimirovich tel.: (423) 242-84-92.