Developmental deviations and difficulties conceiving a child are often associated with inherited disorders. If one of the parents has relatives suffering from genetic diseases, or he himself is a carrier, it is advisable to undergo testing before planning the birth of a baby. Doctors take a karyotype test if they suspect pathologies of chromosomes or DNA molecules. To conduct the study, blood is taken from the patient and treated with a staining compound. After processing, the size, shape and number of chromosomes are examined under a microscope.

Definition

A karyotype is an individual set of chromosomes, which has its own characteristics for each specific biological species and individual. A person has only 23 pairs of chromosomes, that is, a total of 46. Of the twenty-three pairs, only one determines sex, and the rest have no differences in structure. Genetic karyotype analysis allows you to identify abnormalities in the composition or structure of chromosomes. Thanks to this study, doctors can take timely measures to prevent the pathology from causing serious complications, including the death of the fetus.

Important! It is enough for future parents to undergo karyotyping once in their life to ensure the absence or presence of pathologies.

When to take a test

The analysis is relevant for people of any age, because not everyone has been examined by a geneticist since early childhood. There are no contraindications for pregnant and nursing mothers. But first of all, research is required for newborns, for whom early diagnosis will help identify dangerous genetic diseases that affect life expectancy. In-hospital analysis for the karyotype of spouses is often carried out as prescribed by a doctor, but not everyone knows what kind of examination this is. For couples wishing to have a child, examination is indicated in the following cases:

• After repeated unsuccessful attempts to conceive.
• Menstrual irregularities.
• If there have been previous miscarriages or stillbirths.
• In previously born children, delays in mental or physical development were recorded.
• Already at the stage of pregnancy, developmental disorders were detected in the fetus.
• If the future mother and father are close relatives.
• If one of the parents has bad habits.
• Living in a region with an unfavorable environmental situation or working in a hazardous industry.
• Planning your first pregnancy after 35 years - the reason lies in the fact that chromosomes can change with age.
• If parents have genetic diseases, even if healthy children were born before.

Attention! Modern doctors advise all couples to get tested, since not every carrier exhibits pathologies, and therefore many are not aware of them.

Problems, including infertility, are identified when a person decides to have a child.

How the research is carried out

The analysis is taken during the metaphase period, which lasts from two to ten minutes. It is at this moment that it is easiest to examine the chromosomes through a microscope. There are three ways to detect abnormalities - molecular, cytogenetic and molecular targeted. It is up to the doctor to select one method or another. Before the karyotype analysis is carried out, you need to prepare:

• To cure colds, if a person is sick, then you can get tested no earlier than two weeks after recovery.
• 30 days before visiting the hospital, stop taking antibiotics or reduce their consumption according to the doctor’s instructions.
• Do not drink alcohol for three days before testing.
• On the day of the test, you should have a hearty breakfast.

Venous blood is taken for testing. The material obtained from the patient is treated with a dye to identify chromosomes. Next, the doctor takes several pictures, which make it possible to determine the number of DNA molecules and pathological changes.

Important. The molecular method is necessary to detect small areas of structural abnormalities of chromosomes less than 5 million nucleotides in size.

For more detailed diagnostics, an advanced or targeted molecular method is used.

How to decrypt

For representatives of the stronger sex, the normal karyotype analysis results are 46, XY, and for women - 46, XX. The number 46 indicates the normal number of chromosomes, and the X and Y at the end indicate the shape, structure and size of a healthy person - these indicators differ for men and women. Based on the test results, the doctor will make several notes on the form. Their decoding will help you understand medical terms:

1. Translocation - a chromosome rearrangement has occurred. If the patient has a balanced translocation, then it most likely will not manifest itself. If unbalanced, serious deviations are possible.
2. Mosaicism - cells with genetic characteristics different from normal are found.
3. Trisomy - this pathology occurs most often; the patient has an extra chromosome. The most common occurrence is the appearance of a copy of chromosome 21, leading to diseases such as Down syndrome.
4. Inversion - a section of a chromosome is rotated 180 degrees.
5. Monosomy is only one of the pairs of homologous chromosomes in a genotype.
6. Deletion – a fragment of a chromosome is lost.

What to do if deviations are found

You should not assume that anomalies in carinotype analysis always indicate that a married couple will have a sick child, or that they will be childless altogether. For example, parents with a balanced translocation may give birth to a healthy baby who will not have chromosomal pathologies. Even though the prices for karyotype analysis are high and start at three thousand rubles, it is undesirable to refuse it. Perhaps, based on the results, the doctor will advise you to undergo treatment and only then plan a pregnancy.

Attention! If a woman knows that she will have a child with pathologies, she needs to pay attention to a healthy lifestyle and follow the doctor’s recommendations.

Genetic abnormalities can occur in different ways. With trisomy of the thirteenth and eighteenth chromosomes, children die in the first year of life. People with Down syndrome have mental retardation, but the mortality rate is much lower than with similar diseases. Abnormalities of sex chromosomes, such as Shereshevsky-Turner syndrome, often lead to infertility, but a person with these disorders can live to old age. And with monosomy X, about 5% of women have the opportunity to give birth to a baby. It is important to consult a geneticist who will accurately diagnose. A genetic disease cannot be completely cured, but if you undergo regular treatment, your quality of life will improve.

What is a karyotype analysis and why do it - a question that concerns everyone who has had to receive a referral for such a study. A karyotype is determined when it is necessary to find out the biological type of a person by his chromosomes - for example, to find out how compatible a couple is and whether they can have healthy offspring.

To test for karyotype, you need to donate blood from a vein, and blood sampling is carried out according to strict rules. If they are violated, the results of the karyotype analysis may be distorted.

General information about karyotype

What is a karyotype test? Any biological organism has its own karyotype - a set of chromosomes of a specific number, size and shape that are characteristic of this species. In humans, for example, the karyotype includes a “set” of forty-six chromosomes, they are paired. Moreover, 22 pairs are the same for both men and women, and one pair, which determines gender, is different.

In order to determine the karyotype, a genetic study of blood cells is required. This is what karyotyping is all about. After the results are available and deciphered, the doctor receives a complete understanding of the genetic characteristics of a man and a woman and can predict their likelihood of conceiving a healthy child.

• if a couple remains infertile for many years;
• pregnancy proceeds with pathologies, the fetus develops various defects while still in the womb;
• the family already has mentally retarded or physically disabled children;
• there are cases of frozen pregnancy or stillbirth in the anamnesis.

Having such information, you can take timely measures and eliminate the problem before a child with a defect is born. The analysis allows you to eliminate male or female infertility and maintain pregnancy until the very end.

The attending physician will tell you in more detail about what karyotyping is, why and why this analysis is recommended, what preparation is needed for the analysis and how its results are interpreted.

When is this research needed?

But when the question arises about the reproductive capacity of a man or a woman, unexpected problems arise:

• male or female infertility;
• persistent miscarriage;
• the birth of physically or mentally handicapped children.

Human chromosomes can change throughout life. This is why primiparous women over 35 years of age must be referred for karyotyping - they are at risk.

1. nulliparous women with a history of several abortions;
2. if it is impossible to conceive a child;
3. after failed IVF;
4. parents of a child or children with any congenital mental or physical defects who have decided to conceive and give birth to another child;
5. married couples in which the husband and wife are close relatives;
6. persons who permanently reside and work (have lived and worked) in an environmentally unfavorable area;
7. those men and women who suffered (are suffering) from alcoholism or drug addiction.

It is advisable to carry out karyotyping for those persons who, due to their professional duties, are exposed to the harmful effects of external factors - chemical, radiation or physical.

Karyotype analysis is also important for the fetus. With its help, you can identify the development of certain congenital pathologies and defects and make a decision on whether to continue the pregnancy or to terminate it.

How to take the test correctly

Blood analysis can be carried out using two methods - conventional or molecular.

Molecular karyotyping - in turn - is divided into three types:

• standard;
• targeted;
• extended.

The doctor will determine what type of research is necessary and will provide the necessary information. Before donating blood for any type of genetic research, you need to properly prepare.

The preparation is as follows:

• One month before the set date for blood sampling for analysis, you should stop taking hormonal and antibacterial drugs. If you are taking any medications for chronic diseases, you must inform your doctor about this. They are either temporarily canceled or the dosage is reduced as much as possible.
• For at least two weeks before the study, the patient should not have any infectious diseases, even rhinitis or a cold.
• A few days before the test, you should stop drinking alcohol and caffeine, and preferably not smoke.
• When donating blood for karyotype, it is not advisable to eat food; it is better to undergo the procedure early in the morning on an empty stomach.

The analysis is carried out using the staining method, the results will be ready in 10-14 days. In a healthy person who does not have any disorders at the genetic level, 22 chromosome pairs will be found, completely identical and non-defective, and another 1 pair of sex chromosomes of type XX in men and type XY in women.

If the results of the analysis are different, this is an explanation for male or female infertility, a woman’s inability to bear a child, congenital pathologies in the fetus, unsuccessful attempts at artificial insemination and other problems with conception, pregnancy, and child development.

Unfortunately, due to the fairly high cost, not everyone can afford a blood karyotype test, which makes it impossible for many couples to independently give birth to healthy offspring.

And not every medical center performs such tests; residents of remote regions and small settlements have to go to a large regional center. But in the end, getting rid of infertility and a healthy child are worth any cost.

Head of department
"Oncogenetics"

Zhusina
Yulia Gennadievna

Graduated from the Pediatric Faculty of Voronezh State Medical University. N.N. Burdenko in 2014.

2015 - internship in therapy at the Department of Faculty Therapy of VSMU named after. N.N. Burdenko.

2015 - certification course in the specialty “Hematology” at the Hematology Research Center in Moscow.

2015-2016 – therapist at VGKBSMP No. 1.

2016 - the topic of the dissertation for the degree of Candidate of Medical Sciences “study of the clinical course of the disease and prognosis in patients with chronic obstructive pulmonary disease with anemic syndrome” was approved. Co-author of more than 10 published works. Participant of scientific and practical conferences on genetics and oncology.

2017 - advanced training course on the topic: “interpretation of the results of genetic studies in patients with hereditary diseases.”

Since 2017, residency in the specialty “Genetics” on the basis of RMANPO.

Head of department
"Genetics"

Kanivets
Ilya Vyacheslavovich

Kanivets Ilya Vyacheslavovich, geneticist, candidate of medical sciences, head of the genetics department of the medical genetic center Genomed. Assistant at the Department of Medical Genetics of the Russian Medical Academy of Continuing Professional Education.

He graduated from the Faculty of Medicine of the Moscow State Medical and Dental University in 2009, and in 2011 – a residency in the specialty “Genetics” at the Department of Medical Genetics of the same university. In 2017, he defended his dissertation for the degree of Candidate of Medical Sciences on the topic: Molecular diagnostics of copy number variations of DNA sections (CNVs) in children with congenital malformations, phenotypic anomalies and/or mental retardation using high-density SNP oligonucleotide microarrays.”

From 2011-2017 he worked as a geneticist at the Children's Clinical Hospital named after. N.F. Filatov, scientific advisory department of the Federal State Budgetary Institution “Medical Genetic Research Center”. From 2014 to the present, he has been heading the genetics department of the Genomed Medical Center.

Main areas of activity: diagnosis and management of patients with hereditary diseases and congenital malformations, epilepsy, medical and genetic counseling of families in which a child was born with hereditary pathology or developmental defects, prenatal diagnosis. During the consultation, clinical data and genealogy are analyzed to determine the clinical hypothesis and the necessary amount of genetic testing. Based on the results of the survey, the data are interpreted and the information received is explained to the consultants.

He is one of the founders of the “School of Genetics” project. Regularly gives presentations at conferences. Gives lectures for geneticists, neurologists and obstetricians-gynecologists, as well as for parents of patients with hereditary diseases. He is the author and co-author of more than 20 articles and reviews in Russian and foreign journals.

Area of ​​professional interests is the introduction of modern genome-wide studies into clinical practice and interpretation of their results.

Reception time: Wed, Fri 16-19

Head of department
"Neurology"

Sharkov
Artem Alekseevich

Sharkov Artyom Alekseevich– neurologist, epileptologist

In 2012, he studied under the international program “Oriental medicine” at Daegu Haanu University in South Korea.

Since 2012 - participation in the organization of the database and algorithm for interpreting genetic tests xGenCloud (https://www.xgencloud.com/, Project Manager - Igor Ugarov)

In 2013 he graduated from the Pediatric Faculty of the Russian National Research Medical University named after N.I. Pirogov.

From 2013 to 2015, he studied at a clinical residency in neurology at the Federal State Budgetary Institution "Scientific Center of Neurology".

Since 2015, he has been working as a neurologist and researcher at the Scientific Research Clinical Institute of Pediatrics named after Academician Yu.E. Veltishchev GBOU VPO RNIMU im. N.I. Pirogov. He also works as a neurologist and a doctor in the video-EEG monitoring laboratory at the clinics of the Center for Epileptology and Neurology named after. A.A. Kazaryan" and "Epilepsy Center".

In 2015, he completed training in Italy at the school “2nd International Residential Course on Drug Resistant Epilepsies, ILAE, 2015”.

In 2015, advanced training - “Clinical and molecular genetics for medical practitioners”, RDKB, RUSNANO.

In 2016, advanced training - “Fundamentals of molecular genetics” under the guidance of a bioinformatician, Ph.D. Konovalova F.A.

Since 2016 - head of the neurological direction of the Genomed laboratory.

In 2016, he completed training in Italy at the school “San Servolo international advanced course: Brain Exploration and Epilepsy Surger, ILAE, 2016”.

In 2016, advanced training - “Innovative genetic technologies for doctors”, “Institute of Laboratory Medicine”.

In 2017 – school “NGS in Medical Genetics 2017”, Moscow State Research Center

Currently conducting scientific research in the field of genetics of epilepsy under the guidance of Professor, Doctor of Medical Sciences. Belousova E.D. and professor, doctor of medical sciences. Dadali E.L.

The topic of the dissertation for the degree of Candidate of Medical Sciences “Clinical and genetic characteristics of monogenic variants of early epileptic encephalopathies” has been approved.

The main areas of activity are the diagnosis and treatment of epilepsy in children and adults. Narrow specialization – surgical treatment of epilepsy, genetics of epilepsy. Neurogenetics.

Scientific publications

Sharkov A., Sharkova I., Golovteev A., Ugarov I. “Optimization of differential diagnosis and interpretation of genetic testing results using the XGenCloud expert system for some forms of epilepsy.” Medical Genetics, No. 4, 2015, p. 41.
*
Sharkov A.A., Vorobyov A.N., Troitsky A.A., Savkina I.S., Dorofeeva M.Yu., Melikyan A.G., Golovteev A.L. "Epilepsy surgery for multifocal brain lesions in children with tuberous sclerosis." Abstracts of the XIV Russian Congress "INNOVATIVE TECHNOLOGIES IN PEDIATRICS AND CHILDREN'S SURGERY." Russian Bulletin of Perinatology and Pediatrics, 4, 2015. - p.226-227.
*
Dadali E.L., Belousova E.D., Sharkov A.A. "Molecular genetic approaches to the diagnosis of monogenic idiopathic and symptomatic epilepsies." Thesis of the XIV Russian Congress "INNOVATIVE TECHNOLOGIES IN PEDIATRICS AND CHILDREN'S SURGERY." Russian Bulletin of Perinatology and Pediatrics, 4, 2015. - p.221.
*
Sharkov A.A., Dadali E.L., Sharkova I.V. “A rare variant of early epileptic encephalopathy type 2 caused by mutations in the CDKL5 gene in a male patient.” Conference "Epileptology in the system of neurosciences". Collection of conference materials: / Edited by: prof. Neznanova N.G., prof. Mikhailova V.A. St. Petersburg: 2015. – p. 210-212.
*
Dadali E.L., Sharkov A.A., Kanivets I.V., Gundorova P., Fominykh V.V., Sharkova I.V. Troitsky A.A., Golovteev A.L., Polyakov A.V. A new allelic variant of myoclonus epilepsy type 3, caused by mutations in the KCTD7 gene // Medical genetics. - 2015. - v. 14. - No. 9. - p. 44-47
*
Dadali E.L., Sharkova I.V., Sharkov A.A., Akimova I.A. “Clinical and genetic features and modern methods for diagnosing hereditary epilepsies.” Collection of materials “Molecular biological technologies in medical practice” / Ed. Corresponding member RAIN A.B. Maslennikova.- Issue. 24.- Novosibirsk: Akademizdat, 2016.- 262: p. 52-63
*
Belousova E.D., Dorofeeva M.Yu., Sharkov A.A. Epilepsy in tuberous sclerosis. In "Brain diseases, medical and social aspects" edited by Gusev E.I., Gekht A.B., Moscow; 2016; pp.391-399
*
Dadali E.L., Sharkov A.A., Sharkova I.V., Kanivets I.V., Konovalov F.A., Akimova I.A. Hereditary diseases and syndromes accompanied by febrile seizures: clinical and genetic characteristics and diagnostic methods. //Russian Journal of Child Neurology.- T. 11.- No. 2, p. 33- 41. doi: 10.17650/ 2073-8803-2016-11-2-33-41
*
Sharkov A.A., Konovalov F.A., Sharkova I.V., Belousova E.D., Dadali E.L. Molecular genetic approaches to the diagnosis of epileptic encephalopathies. Collection of abstracts “VI BALTIC CONGRESS ON CHILD NEUROLOGY” / Edited by Professor Guzeva V.I. St. Petersburg, 2016, p. 391
*
Hemispherotomy for drug-resistant epilepsy in children with bilateral brain damage Zubkova N.S., Altunina G.E., Zemlyansky M.Yu., Troitsky A.A., Sharkov A.A., Golovteev A.L. Collection of abstracts “VI BALTIC CONGRESS ON CHILD NEUROLOGY” / Edited by Professor Guzeva V.I. St. Petersburg, 2016, p. 157.
*
*
Article: Genetics and differentiated treatment of early epileptic encephalopathies. A.A. Sharkov*, I.V. Sharkova, E.D. Belousova, E.L. Yes they did. Journal of Neurology and Psychiatry, 9, 2016; Vol. 2doi: 10.17116/jnevro 20161169267-73
*
Golovteev A.L., Sharkov A.A., Troitsky A.A., Altunina G.E., Zemlyansky M.Yu., Kopachev D.N., Dorofeeva M.Yu. "Surgical treatment of epilepsy in tuberous sclerosis" edited by Dorofeeva M.Yu., Moscow; 2017; p.274
*
New international classifications of epilepsies and epileptic seizures of the International League Against Epilepsy. Journal of Neurology and Psychiatry named after. C.C. Korsakov. 2017. T. 117. No. 7. P. 99-106

Head of department
"Prenatal diagnosis"

Kyiv
Yulia Kirillovna

In 2011 she graduated from the Moscow State Medical and Dental University. A.I. Evdokimova with a degree in General Medicine. She studied residency at the Department of Medical Genetics of the same university with a degree in Genetics.

In 2015, she completed an internship in Obstetrics and Gynecology at the Medical Institute for Advanced Training of Physicians of the Federal State Budgetary Educational Institution of Higher Professional Education "MSUPP"

Since 2013, he has been conducting consultations at the State Budgetary Institution "Center for Family Planning and Reproduction" of the Department of Health.

Since 2017, he has been the head of the “Prenatal Diagnostics” direction of the Genomed laboratory

Regularly makes presentations at conferences and seminars. Gives lectures for various specialist doctors in the field of reproduction and prenatal diagnostics

Provides medical and genetic counseling to pregnant women on prenatal diagnostics in order to prevent the birth of children with congenital malformations, as well as families with presumably hereditary or congenital pathologies. Interprets the obtained DNA diagnostic results.

SPECIALISTS

Latypov
Arthur Shamilevich

Latypov Artur Shamilevich is a geneticist doctor of the highest qualification category.

After graduating from the medical faculty of the Kazan State Medical Institute in 1976, he worked for many years, first as a doctor in the office of medical genetics, then as the head of the medical-genetic center of the Republican Hospital of Tatarstan, the chief specialist of the Ministry of Health of the Republic of Tatarstan, and as a teacher in the departments of the Kazan Medical University.

Author of more than 20 scientific papers on problems of reproductive and biochemical genetics, participant in many domestic and international congresses and conferences on problems of medical genetics. He introduced methods of mass screening of pregnant women and newborns for hereditary diseases into the practical work of the center, and performed thousands of invasive procedures for suspected hereditary diseases of the fetus at different stages of pregnancy.

Since 2012, she has been working at the Department of Medical Genetics with a course in prenatal diagnostics at the Russian Academy of Postgraduate Education.

Area of ​​scientific interests: metabolic diseases in children, prenatal diagnostics.

Reception hours: Wed 12-15, Sat 10-14

Doctors are seen by appointment.

Geneticist

Gabelko
Denis Igorevich

In 2009 he graduated from the Faculty of Medicine of KSMU named after. S. V. Kurashova (specialty “General Medicine”).

Internship at the St. Petersburg Medical Academy of Postgraduate Education of the Federal Agency for Health and Social Development (specialty "Genetics").

Internship in Therapy. Primary retraining in the specialty “Ultrasound diagnostics”. Since 2016, he has been an employee of the department of the Department of Fundamental Principles of Clinical Medicine of the Institute of Fundamental Medicine and Biology.

Area of ​​professional interests: prenatal diagnosis, use of modern screening and diagnostic methods to identify genetic pathology of the fetus. Determining the risk of recurrence of hereditary diseases in the family.

Participant of scientific and practical conferences on genetics and obstetrics and gynecology.

Work experience 5 years.

Consultation by appointment

Doctors are seen by appointment.

Geneticist

Grishina
Kristina Alexandrovna

She graduated from the Moscow State Medical and Dental University in 2015 with a degree in General Medicine. In the same year, she entered residency in the specialty 08/30/30 “Genetics” at the Federal State Budgetary Institution “Medical Genetics Research Center”.
She was hired at the Laboratory of Molecular Genetics of Complexly Inherited Diseases (headed by Dr. A.V. Karpukhin) in March 2015 as a research assistant. Since September 2015, she has been transferred to the position of research assistant. He is the author and co-author of more than 10 articles and abstracts on clinical genetics, oncogenetics and molecular oncology in Russian and foreign journals. Regular participant in conferences on medical genetics.

Area of ​​scientific and practical interests: medical and genetic counseling of patients with hereditary syndromic and multifactorial pathology.

A consultation with a geneticist allows you to answer the following questions:

Are the child’s symptoms signs of a hereditary disease? what research is needed to identify the cause determining an accurate forecast recommendations for conducting and evaluating the results of prenatal diagnostics everything you need to know when planning a family consultation when planning IVF on-site and online consultations

took part in the scientific and practical school "Innovative genetic technologies for doctors: application in clinical practice", the conference of the European Society of Human Genetics (ESHG) and other conferences dedicated to human genetics.

Conducts medical and genetic counseling for families with presumably hereditary or congenital pathologies, including monogenic diseases and chromosomal abnormalities, determines indications for laboratory genetic studies, and interprets the results of DNA diagnostics. Consults pregnant women on prenatal diagnostics to prevent the birth of children with congenital malformations.

Geneticist, obstetrician-gynecologist, candidate of medical sciences

Kudryavtseva
Elena Vladimirovna

Geneticist, obstetrician-gynecologist, candidate of medical sciences.

Specialist in the field of reproductive counseling and hereditary pathology.

Graduated from the Ural State Medical Academy in 2005.

Residency in Obstetrics and Gynecology

Internship in the specialty "Genetics"

Professional retraining in the specialty “Ultrasound diagnostics”

Areas of activity:

• Infertility and miscarriage
Vasilisa Yurievna



She is a graduate of the Nizhny Novgorod State Medical Academy, Faculty of Medicine (specialty “General Medicine”). She graduated from clinical residency at FBGNU "MGNC" with a degree in Genetics. In 2014, she completed an internship at the Maternity and Childhood Clinic (IRCCS materno infantile Burlo Garofolo, Trieste, Italy).

Since 2016, he has been working as a consultant physician at Genomed LLC.

Regularly participates in scientific and practical conferences on genetics.

Main activities: Consulting on clinical and laboratory diagnostics of genetic diseases and interpretation of results. Management of patients and their families with suspected hereditary pathology. Consulting when planning pregnancy, as well as during pregnancy, on prenatal diagnostics in order to prevent the birth of children with congenital pathologies.

Karyotyping is the study of a person’s chromosome set, that is, his karyotype. The correct human karyotype consists of 46 chromosomes. Of these, 44 chromosomes are identical in structure, and 2 different from them are responsible for the difference in sex. Diseases that are accompanied by pathological changes in the karyotype are called chromosomal. For example, Down syndrome. The karyotype for this disease consists of 47 chromosomes, which is exactly what answers.

The need for karyotyping

The doctor prescribes karyotyping for married couples after the woman has had several unsuccessful pregnancies. Deviations in the structure of chromosomes due to an unsuccessful match of genes in parents can cause infertility, miscarriages and the birth of children with genetic diseases. Karyotyping allows you to find out the cause of infertility and predict the likelihood of spouses having children with chromosomal abnormalities.

Karyotyping does not need to be performed for couples who are at the initial stage of planning a pregnancy. Such an analysis is usually carried out once in a lifetime, since a person’s karyotype is unchanged.

Some diseases do not always mean the birth of only sick children. In this case, a special procedure is performed during pregnancy to study the karyotype of the fetus. The procedure is carried out on cells taken from the membranes of the fetus. If there are gross changes, the pregnancy is terminated.

How is karyotyping performed?

Determining a karyotype is a very complex and lengthy procedure that is carried out only in specialized institutions - a reproductive center. For analysis, venous blood is most often needed, from which lymphocytes are later isolated; less often, bone marrow or skin cells are taken.

An important feature of the analysis is that the material must be examined immediately after its receipt, since there is a possibility of cell death. After receiving the necessary cells, they are sent to a special incubator and a substance is added that causes the cells to actively multiply by division.

Then the substance colchicine is added, which stops cell division. After this, the cells are stained with a special dye, and under a microscope you can see the chromosomes in the cell nucleus.

The karyotype of a cell is chaotic, so a specialist photographs it and makes a map, arranging the chromosomes in pairs. Then the analysis is carried out.

The results of the study can be found out in 1-2 weeks.

When planning to conceive a child, future parents fear the possibility of genetic abnormalities in their offspring. An error of nature, which cannot be foreseen or corrected, is rare, but no one is immune from it. This was the case before, before the advent of a new method of research at the chromosomal level - karyotyping. What kind of animal it is, what it looks like and who is recommended to go through first - let's figure it out.

What does karyotyping study?

In the nucleus of a living cell there are chromosomes - thread-like bodies containing DNA with a certain gene sequence, which contains hereditary information. The task of chromosomes is to store information and transmit it to descendants.

A karyotype is understood as a complete set of chromosomes, as well as the characteristics of their number, size and structure.

Scientists first described chromosomes in the second half of the 19th century, and the chromosome theory of heredity was substantiated at the beginning of the 20th century. The term “karyotype” was proposed in 1924 by the Soviet geneticist Levitsky.

The standard human karyotype is 46 chromosomes, comprising 23 pairs. Such a set is contained in almost every cell of the body. There are:

• autosomal chromosomes - 44 pieces or 22 pairs; are responsible for the color of eyes, skin, hair type and color, quality of vision, height, level of intelligence, and so on, transmitted to generations;
• sex chromosomes - 2 pieces or 1 pair; in response to characteristics of male or female; in the karyotype of women, both chromosomes are the same and are designated XX; in men - different, one is equal-armed (X), the other is reduced rod-shaped (Y), therefore they are designated XY.

The child receives half of the karyotype chromosomes from the mother, and half from the father.

Karyotype of a person with an extra chromosome - on the diagram there are 47 instead of 46

In the 70s of the 20th century, they experimented with coloring chromosomes - and found that certain dyes led to the appearance of transverse stripes on the “particles of heredity”; different couples acquired an individual set of stripes.

Scientists adopted the method of differential staining and compiled karyograms: each pair of chromosomes was given a number, and each had its characteristic stripes drawn. Karyotype records were unified. So, normally:

• woman's karyotype - 46, XX;
• The man's karyotype is 46, XY.

Here's what chromosomal mutations are called:

• 47, XX, 21+ - decoding means that a woman has a third chromosome in the 21st pair (the + or - signs indicate the presence of an additional or absence of the main chromosome);
• 47, XXY - an extra sex X chromosome was found in a man (Klinefelter syndrome).

Thus, they gradually came to a new method of cytogenetic research - karyotyping. From now on, by poring over colored chromosomes, scientists are able to find out with almost 100% accuracy what the likelihood is that certain parents will have a baby with genetic developmental anomalies.

Who is karyotyping indicated for?

Karyotype analysis is optional; however, when planning to have a child, spouses will avoid a shocking “discovery” in the form of a defective baby if they know the structures of their own sets of chromosomes in advance.

Among all hereditary diseases, those caused by chromosomal abnormalities occupy a leading position. On average, one in a hundred newborns are susceptible to such pathologies.

Hereditary diseases “pop up” unexpectedly in members of the genus; Generation after generation can be born healthy, when suddenly a baby appears with a very bad syndrome. Karyotyping will help calculate the risk of a genetic disease. A geneticist determines how compatible a man and a woman are at the genetic level by studying the karyotypes of both.

It happens that spouses learn about a new research method late, when a new life is already developing in the mother’s womb. In the 1st trimester it is also possible to get tested for karyotype; if the result shows the threat of an incurable disease in the fetus, the woman retains the opportunity to get rid of the child, as time allows. However, many expectant mothers, despite the difficulties, decide to give birth to a “special” baby.

Modern methods also allow us to study the karyotype of the child himself - in this case we talk about prenatal karyotyping.

Karyotype analysis is not a cheap procedure, the price is around 6,700 rubles. It is possible that such a test will eventually be required of all future parents; In Europe, karyotyping has not raised any surprising questions for a long time, but in Russia it has not yet taken root. However, the doctor will prescribe a karyotype test for partners when:

• one or both future parents have crossed the 35-year mark;
• one of the couple had hereditary pathologies in the family;
• the future mother and father are close blood relatives;
• a woman is trying to get pregnant to no avail, the causes of infertility have not been established;
• a number of IVF attempts were unsuccessful;
• the woman has previously had miscarriages (three or more) or the fetus has repeatedly died in the womb;
• a woman is diagnosed with a hormonal imbalance or a man has weak sperm identified based on the results of a special analysis - a spermogram;
• one of the two or both work in hazardous industries with hazardous chemicals or have received an increased dose of radiation;
• future parents, one or both, have bad habits - smoke, drink alcohol, take drugs; Also at risk are those who uncontrollably swallow strong drugs;
• The partners have already given birth to a child with serious pathologies.

Since the composition and structure of chromosomes remain unchanged throughout life, karyotyping only needs to be done once.

What diseases are detected in the fetus by karyotype analysis?

Chromosomal mutations cause irreversible impairments in mental development and severe physical illnesses. This is what is diagnosed using cytogenetic research:

• monosomy - the absence of an X chromosome in a pair of sex chromosomes; as a result, Shereshevsky-Turner syndrome develops - a genetic pathology leading to short stature, deformation of the joints of both elbows, and insufficient puberty;
• trisomy - the third chromosome in the originally conceived “duet”; if an extra one appears in the 21st pair, Down syndrome is diagnosed - mental retardation is expressed in a poor vocabulary, slurred speech, inability to think abstractly, absent-mindedness; when the “third wheel” appears in the 13th pair, Patau syndrome is evident - severe congenital defects do not give a chance to live long, sick children reach a maximum of 10 years;

  Those born with Down syndrome remain seven-year-old children forever, but this genetic anomaly, unlike Patau syndrome, allows them to live into old age

• duplication - a section of a chromosome is doubled; is more common on chromosome 9, then the pathology leads to congenital deformities, impaired renal function, mental retardation; a quarter of patients with this diagnosis live to an old age;
• deletion - a segment of a chromosome disappears; when a segment in chromosome 9 is lost, Alfie syndrome is diagnosed, among the signs are kidney hydronephrosis, cardiovascular system defects, moderate mental retardation, obedient and affectionate children; when a section in chromosome 13 is lost, Orbeli syndrome occurs - accompanied by severe defects of internal organs, idiocy; part of chromosome 5 is lost - an anomaly called “cat cry” will appear: the baby will receive birth defects, in addition, will cry for a long time and loudly;

  Hysterical, causeless crying is one of the signs of a chromosomal abnormality called “cat cry”; The baby's sobs really resemble loud meows

• inversion - rotation of a chromosome segment by 180 degrees; as a rule, they do not disfigure the appearance and do not lead to pathologies; scientists, however, suspect that when a segment in chromosome 9 is inverted, a woman’s risk of miscarriage increases by 30%;
• translocation - a segment of one chromosome is attached to another; such linked chromosomes lead to infertility and miscarriages; children are born with developmental defects.

Using karyotyping, the state of genes is assessed, in some cases the following is discovered:

• a gene mutation that causes the formation of blood clots - the expectant mother is at risk of miscarriage, and sometimes infertility;
• gene disorder of the sex Y chromosome - the diagnosis of “infertility” is made to a man; in order for a partner to become pregnant, she will have to use donor sperm;
• a gene mutation that interferes with the body's ability to rid itself of toxins;
• a mutation in the gene regulator of cystic fibrosis, a severe incurable disease in which the functions of the digestive tract and respiratory organs are impaired.

One of the most famous hereditary diseases is hemophilia, or the “royal disease”; caused by a gene mutation on the sex X chromosome. The peculiarity of the pathology is that the carriers of the defective chromosome are women, and hemophilia is transmitted exclusively to male descendants. Manifested by poor blood clotting. A similar disease was identified in the English Queen Victoria, from whom her great-grandson, the son of the Russian Emperor Nicholas II, Alexei, received the mutated gene on his mother’s side.

The son of the last Russian emperor, Tsarevich Alexei, suffered from hemophilia from birth; received a genetic disease from his mother, Empress Alexandra Feodorovna

In addition, karyotyping reveals the likely inheritance of the following diseases:

• hypertension - persistent increase in blood pressure;
• myocardial infarction - necrosis of an area of ​​the myocardium due to lack of blood supply;
• diabetes mellitus - impaired glucose absorption;
• joint pathologies.

How is a karyotype analysis done?

The procedure is not easy, so it is not worth doing in a regular clinic. A competent geneticist and thorough laboratory research using modern technology are required; It is better to contact reproductive centers.

If karyotyping is carried out according to all the rules, an error is likely in one case out of a hundred.

Preparation

To obtain an accurate chromosomal “portrait”, laboratory technicians will have to spend more than one day of painstaking work. A sample of venous blood is taken for research, and the cells in the resulting biomaterial should grow normally. To avoid having to donate blood twice, you should start preparing for the procedure two weeks before the “event”.

To maintain blood cell growth you need:

Karyotype analysis is safe; neither those planning a pregnancy nor expectant mothers should be afraid of the procedure.

Laboratory research

To begin with, blood is taken from a vein from each of the potential parents and immediately sent for analysis before the cells die.

Doctors first of all advise “aged” expectant mothers to find out their karyotype, and to do this, donate blood from a vein for analysis

Only 12–15 lymphocytes are enough for the study.

Results

You received two conclusions in which you see 46 XX (for a woman) and 46 XY (for a man); everything is fine, your karyotypes are normal, give birth calmly.

If the issued paper contains a more complex system of “squiggles,” the geneticist calls the potential parents for a consultation. What's next:

• the doctor explains how great the risk is for a couple to have a defective baby, which of the partners turns out to be a carrier of the wrong set of chromosomes or a gene mutation;
• the doctor tells what parents can do in each specific case: take donor sperm (or donor egg) for conception, be content with adopting a child, or still take a risk and give birth to their own; it happens that chromosomal abnormalities lead to a low percentage of probable pathologies in the fetus;
• When a pregnant woman is warned about the possibility of having a child with genetic abnormalities, the doctor, as a rule, advises having an abortion, but the woman herself - and no one else - will decide.

The result of karyotyping is unpredictable - future parents may be in for an unpleasant surprise in the form of the presence of chromosomal abnormalities in one or both of them; the doctor is obliged to suggest a way out of the situation

Sometimes treatment with medications and vitamins prescribed by doctors reduces the risk of abnormalities in the unborn child.

When and how is fetal karyotyping performed?

So, the woman became pregnant without first passing a karyotype test; the partner also neglected the procedure. Already in the 1st trimester, the expectant mother may be recommended karyotyping of the fetus - even in the early stages, the accuracy of the analysis is high and a study of the baby’s karyotype will show whether chromosomal abnormalities have appeared.

The procedure requires a compelling medical reason. In addition to problematic heredity, advanced age and other factors that place a pregnant woman at risk, there are other reasons for concern:

• viral infections picked up by a woman during pregnancy;
• poor blood test results: for example, a low level of AFP (alpha-fetoprotein - a protein mass in the liver and digestive tract) indicates the likely development of Down syndrome in the fetus; An increased level of hCG (pregnancy hormone - human chorionic gonadotropin) warns of the same thing.

An unplanned pregnancy, including from a casual partner, is also fraught with danger: the woman has no idea what hereditary diseases were encountered in the family of the unfamiliar “dad.”

Methods

Prenatal karyotyping is carried out using two methods:

• non-invasive (that is, without penetration through the skin and mucous membranes); consists of an ultrasound procedure with measurement of the fetus and the study of the mother’s blood donated for biochemistry with the identification of markers - violations of the normal content of AFP, hCG, and so on; the method is considered safe for the unborn child;
• invasive (with penetration) - a biopsy procedure is performed; the doctor inserts instruments into the uterine cavity, carefully punctures the amniotic sac and extracts genetic material - placenta cells, umbilical cord blood, a drop of fluid that forms amniotic fluid; the study of biological samples will allow us to obtain a karyotype of the fetus and determine the presence or absence of chromosomal abnormalities.

The advantage of the invasive method is high accuracy and informativeness of diagnosis; the percentage of erroneous results is minimal. Non-invasive testing is not as effective. However, the big disadvantage of the “penetration” method is possible threats to the fetus. Invasion of the fragile intrauterine world threatens with complications, including:

• sudden bleeding;
• leakage of amniotic fluid;
• placental abruption;
• miscarriage.

In truth, such consequences occur rarely - in 2-3% of cases, but doctors are obliged to inform future parents about the risks of the invasive method of fetal karyotyping. By the way, in this way the sex of the unborn child is found out at the beginning of pregnancy, but it is better to satisfy your curiosity a little later so as not to endanger the fetus.

With or without aberrations

Aberration - in other words, a deviation from the norm, an error - these are the same quantitative and structural abnormalities in chromosomes that cause genetic diseases. There are aberrations:

• regular - appear in many or even all cells at once, from the time of conception or after a couple of days;
• irregular - appear as a result of the influence of an unfavorable external environment on the body (radiation, chemical dyes).

To detect traces of the effects of harmful substances on the chromosome set, studying 12–15 lymphocytes is no longer enough. A more detailed genetic examination is required - 100 immune cells are taken for analysis. This is karyotyping with aberrations, as a result of which the woman is prescribed medications to reduce the negative effects of “chemistry” on the body.

Such a complex analysis is prescribed instead of the usual:

• patients and their partners with suspected infertility;
• women who have previously been unable to bear a child;
• women with a number of unsuccessful IVF attempts.

Karyotype analysis with aberrations is a labor-intensive procedure: one highly qualified physician spends a whole working day working on the biomaterial of a single patient. Not every medical center is able to afford the luxury of conducting such studies, so you still have to look for a place to take the test.