How is a DNA test carried out and its accuracy. How reliable are paternity test results?

The paternity test is the most common genetic analysis, which is carried out in a modern laboratory under the supervision of specialists. The subject of the study are the presented samples of biomaterials. This can be a smear from the oral mucosa, saliva, blood, hair, nails, earwax, etc. In more detail, what is suitable for a genetic test for paternity will be explained by a laboratory expert.

The ANO "Center for Genetic Research" conducts a paternity test, the cost of this study may vary depending on the number of test participants. For example, when testing two or more alleged biological fathers.

What can affect the result of a DNA test

Nothing, the human cell remains unchanged from the beginning to the end of life. Even if blood transfusions or various health problems occur, they cannot affect or distort the result. But, if after a blood transfusion, 1 month has not passed, then there is a low probability that a mixed DNA profile will be isolated during the processing of the biomaterial. If the blood transfusion was recent, then a DNA test is best done by taking a swab from the oral cavity. Reliability by blood and buccal method has equally high reliability.

What is needed for a DNA test

You need to contact the experts at the ANO Center for Genetic Expertise. Experts will acquaint you with the rules for self-sampling of biomaterial or offer to conduct sampling in our laboratory. If you are satisfied with the paternity test in terms of cost and deadlines, we fill out the accompanying documents, accept biomaterial samples and perform the test.

Purpose of a DNA Test

The goal of our activity is to approach the identification of genetic studies as professionally as possible. Not only the establishment of paternity is the reason for contacting us. A DNA test can be carried out in order to establish motherhood, the relationship of brothers, sisters, blessed relatives. There are a lot of reasons, but a DNA test allows people to find the answer to exciting questions related to kinship and paternity.

• About how the paternity test is performed, the cost and timing of the analysis, other information of interest can be obtained by phone or at a preliminary consultation with an expert.

If the purpose of establishing paternity is to prove and bring the biological father to financial responsibility, it is necessary to perform a genetic study officially. Anonymous research can only serve as a basis for filing a lawsuit. For the court, an anonymous study is an indirect fact, therefore, an official genetic study will be assigned already with the identification of the test participants, then the result will have legal force.

If an expert on biological material has established paternity, then this biological material really belongs to the child and the true father.

Direct spoofing of results is possible in several ways:

1. The biological material of the intended child was replaced with the biological material of another (if you have another) child.
2. Your biological material has been replaced with the biological material of the true father.
3. Outright falsification of data: in the examination they simply wrote the "necessary" alleles.

The probability of falsification is extremely small and there are even articles punishing offenses for this (Article 57 of the Code of Criminal Procedure of the Russian Federation, Article 310 of the Criminal Code of the Russian Federation). Therefore, it is unlikely that the expert would agree to falsification of facts. On the other hand, it is easier to replace the biomaterial, but in this case it should have fallen into the hands of the interested party, which is unacceptable. Having traced the path of the biomaterial and established that it could fall into the hands of an interested party, it would be correct to apply for a re-examination.

The most correct thing, in our opinion, without understanding the intricacies of the examination and as well as the route of the biological material, is to carry out a repeated genetic examination.

The Y-chromosomal haplogroup can be established by determining the allelic variants of polymorphic loci of the Y-chromosome. This can be done in our organization.

How reliable are paternity test results?

The accuracy of the results is 100% for a negative result when the man is not the biological father, and 99.99% for confirmation of paternity.

Do you conduct a DNA examination of an exhumed corpse? Who collects the material and how?

Yes, we do. To conduct an expert study, nail plates, hair and bone samples are usually removed from the exhumed corpse. In many respects it depends on what stage of decomposition the troupe is at. Practice shows that nuclear DNA is rapidly destroyed in the tissues of a deceased organism, therefore, the study of an exhumed corpse is possible only by mitochondrial DNA, that is, a genetic examination of mitochondrial DNA is carried out.

If the results of the examination are intended for the court, then (according to Article 16 of the Federal Law 73 of May 31, 2001, as well as Article 85 of the Code of Civil Procedure of the Russian Federation) "the expert does not have the right: to independently collect materials for the production of a forensic examination." How to legally take biomaterial from an exhumed corpse, it would be best to consult with lawyers. On the other hand, it is possible to exhume the corpse and take biomaterial on your own and/or in the presence of other persons (civil servants, forensic experts, etc.). But, in this case, the court may, at its discretion, use the primary act of the forensic medical examination, performed on a private request.

Can you conduct a paternity test if the potential father has died? By analyzing the particles of a dead body or the DNA of living individuals - blood relatives, such as a sister?

If the potential father has died, then an examination to establish paternity can be carried out. This can be done in two ways: 1) By taking biological material from the deceased alleged father. The simplest thing in this case, if the body is not buried, is to cut off the tips of the nails on the fingers. 2) Having received biological material from close relatives of the alleged father, such as a sister or brother. Usually samples of buccal epithelium are taken from living individuals. In both cases, autosomal polymorphic DNA loci are examined.

What is the probability (what percentage) of establishing kinship between grandfather and grandson?

Unfortunately, the accuracy of genetic examination at autosomal loci in the case of grandfather-grandchild relationship is much lower than in the case of father-son relationship. A positive conclusion about kinship is accepted when the probability of kinship is not lower than 80%. On the other hand, if the grandfather is paternal, then it would be best to analyze by examining the loci on the Y chromosome. In such a case, the probability of relationship can be 99.99% (if the alleged grandfather is the true grandfather).

Are 15 loci enough to determine the relationship of paternal brothers? Can they be mailed?

15 loci will not be enough to determine half-blood relationship (kinship between brothers on the father's side). If there are only biomaterial samples from two alleged brothers, then at least 20-25 loci should be analyzed. It is best to take biomaterial for analysis from another close relative of the brother being determined. The probability of relationship is calculated on the basis of population data on the occurrence of alleles. For each locus, the relatedness index is calculated, they are multiplied and form the combined relatedness index. From the combined relationship index, the probability of relationship is calculated. A positive relationship conclusion is issued if the probability of relationship is 80% or more. Biomaterial can be sent by mail.

Is an examination to establish the relationship between the alleged uncle and niece possible?

The relationship between the alleged uncle and niece can be established. At the same time, for a trio (presumed uncle - niece - relative on another line), the probability of obtaining a certain conclusion is much higher than for a duet (presumed uncle - niece).

Do you conduct a genetic examination to establish a consolidated relationship (brother, sister) from one father and different mothers?

Yes, our center conducts genetic examinations to establish a consolidated relationship. To obtain a more reliable result, it is desirable to type not only the alleged half-blood relatives, but also their mothers. If it is impossible to obtain biomaterial from one of the mothers, then another, as close as possible, relative from her side can be included in the study instead. On the other hand, a relationship probability of more than 90% can be obtained by examining a trio - mother of child 1 / child 1 / child 2. By examining the biomaterial of only two alleged half-brothers and sisters, it is rarely possible to obtain a relationship probability of about 90%.

What is the maximum percentage of accuracy possible when establishing the relationship between the sibling of the alleged father and the child of a girl (uncle-niece)?

The probability of a genetic examination involving mother-child (girl)-paternal uncle can be 99.9%. It is generally accepted that when the probability of relationship reaches 80% or more, the relationship is considered proven. In addition to the probability of kinship, in the examination there is the value of "probability ratio" (LR - likelihood ratio). LR - shows how many times the probability of the direct hypothesis (the studied persons are relatives) is greater than the probability of the reverse hypothesis (the studied persons are not relatives).

How many percent is a genetic examination to establish paternity (without exhumation) reliable if the alleged father died, but he still had a brother and mother. Is it possible then to refute the results of this examination if the biological material is taken from the husband's brother or his mother?

The probability of a genetic examination involving a mother, child, alleged paternal uncle (or paternal grandmother) can be 99.9% (if the uncle or grandmother is true relatives). If the child is a boy, then we can still analyze the Y-chromosome markers, in which case the alleles of the Y-chromosome loci in the child and uncle should completely match (if this is a true uncle). The probability of genetic examination will also be about 99.9%.

I have a sister, is it possible to determine whether we are from the same father? What is needed for this?

In order to find out whether you and your sister are descended from the same father or not, we will need samples of the buccal epithelium of you, your sister and mother. If it is possible to take a sample of your father's buccal epithelium, then his too. Samples can be collected at home and brought to us, or handed over at our center. The resulting samples will be sent to experts for genetic testing.

Yes, we can establish your Y-chromosomal haplogroup and thus determine where your ancestors came from. However, to which haplogroup your alleged ancestor (Prince of Lithuania Olgerd Gedeminovich) belonged is not possible due to the lack of his biomaterial. Moreover, DNA genealogy operates in terms of tens of thousands of years, not thousands of years.

On the other hand, having established your haplogroup, you can search for relatives close to you in the corresponding databases and, making contact with them, establish common, more distant relatives of yours. At the moment, we determine belonging to the Y-chromosomal haplogroup by 17 markers of the Y-chromosome.

Can a paternity test be conducted without samples of the father's biomaterial?

Yes maybe. This will require biomaterial samples of the closest relatives of the father - father, mother, siblings (descendants of the same parents), etc. The closer the relative is to the father in terms of pedigree, the more accurate the results will be and the higher the likelihood of kinship. Moreover, it is possible to provide biological material of several paternal relatives, for example: father and mother, several siblings, children from another woman, etc. In this case, the reliability of the examination increases and can reach more than 99.99%.

The father of the child is my own brother, can a DNA test show that I am the father?

No. Siblings have only 50% of the same genes, so if you are not the father of the child, the examination will confirm this.

How to read the DNA test result correctly?

In the expert opinion, there are two main characteristics of kinship - this is the kinship index and the probability of kinship. The relationship index is a number showing the ratio of two probabilities. The relationship index shows how many times the probability of the direct hypothesis (the studied persons are relatives) is greater than the probability of the reverse hypothesis (the studied persons are not relatives).

The second characteristic shows the probability of relationship as a percentage, which is calculated on the basis of the relationship index. A relationship probability below 50% indicates that the alleged relationship is excluded, a probability from 50% to 90% indicates the uncertainty of the results of a DNA study, a probability of 90% or more indicates a significant probability of a relationship.

Are mutations taken into account in the calculation of the probability of relatedness?

Mutations cause a situation where the allele inherited by the child from the father is absent at one or two loci. In the calculation of the relationship index, these mutations are always taken into account, moreover, when a situation arises in which the probability of relationship is in the range from 50% to 90%, we conduct an additional study (11 more DNA loci are examined).

Does the result of a paternity test show the gender of the child?

In the results of DNA analysis, there is a sex marker - amelogenin (AM). Amelogenin is a gene found on the X and Y chromosomes. The results of the analysis indicate not only the gender of the child, but also the gender of all other test participants.

Do you work with bone materials?

Yes, we work with bone material of any age. However, before extracting bone samples from the ground or other soil, be sure to clarify how such samples should be collected, stored and transported. If a genetic examination is planned in the future, then such materials require special care. Remember that any biological material is an excellent food for many microorganisms, so it should be stored dehydrated or frozen.

We can very accurately determine what species the discovered wool belongs to. As a result of the “Genetic expertise to determine the species of biological objects”, we will determine the type of animal to which it belongs.

What standards are used to ensure the accuracy of DNA testing?

Our laboratory uses the international gold standards in the field of genetic research recommended by the American Association of Blood Banks (Guidance for Standards for Relationship Testing Laboratories), as well as the International Society for Forensic Genetics (International Society for Forensic Genetics: Recommendations on biostatistics in parent testing). These standards allow you to obtain reliable results comparable with other laboratories in different countries. In difficult cases of determining kinship, when the probability of kinship is from 50% to 90%, an additional analysis is performed in our laboratory for 11 DNA loci.

Can I use regular ear sticks to collect buccal epithelium?

Yes, you can buy ordinary cotton swabs and take the biomaterial yourself. However, be careful that there is no contamination from another person. If you only use sticks in your home, then you can safely take these sticks, if several people use this pack of cotton buds, then you should buy a new pack and use them to collect the buccal (buccal) epithelium.

How long can buccal epithelial samples be stored on a Q-tip?

The main thing after collecting the buccal epithelium is to dry the Q-tip, so we recommend packing them in a regular paper envelope. In this form, samples are sent to us by mail, and after three to four weeks of delivery by regular mail, they always reach us with DNA suitable for analysis.

Do you perform DNA paternity tests on nails? Does the accuracy of the analysis decrease compared to other samples?

Of course, we do a nail examination. To do this, the nails must be trimmed from several fingers. This will not affect the accuracy of the study, since the DNA in the cells of the whole organism is the same.

Do you keep samples of collected DNA?

No, we destroy DNA samples immediately after testing and receiving results.

Do you perform DNA paternity testing before the baby is born?

Prenatal paternity testing is possible, but we do not recommend it, as taking the child's biological material is difficult for doctors and very dangerous for the child. Of course, it is better to wait for the birth of the child, and then conduct an examination. If you still want to conduct such an examination, then for the study we will need samples of the mother’s biomaterial, the alleged father, as well as the child’s biological material (for example, blood from the umbilical cord or a sample of amniotic fluid). Our center does not collect fetal material, so you need to use the services of any medical institution that conducts the procedure for taking fetal material.

Are there special conditions for storing blood samples? How long can blood be stored?

Vacuum tubes for taking blood samples usually contain an anticoagulant that prevents the blood from clotting and also prevents the destruction of DNA. Such blood is suitable for several weeks when stored at about +4°C. Long-term storage is possible when frozen to -20°C. In the event that blood samples are to be sent, it is advisable to take it on a napkin or gauze folded in several layers, and then dry the resulting blood stains at room temperature. Such samples can be stored at room temperature in a place hidden from sunlight for more than a year.

Can genetic testing be done anonymously?

If a genetic study to establish paternity is performed not by the court, but by private request, then we guarantee the complete anonymity of all information. The results of the study will be known only to the customer or a person authorized by him. If a genetic examination is carried out by a court decision, then the results are submitted to the court and the parties can familiarize themselves with the results of the examination only in court.

Is it possible to determine whether the parts of the corpse are the remains of the same person?

Yes it is possible. The genotype of each person is individual, and if a mismatch of alleles is found in the same loci from different parts of the corpse, this will indicate the presence of two (or more) different human remains.

What to do when one of the parties evades the delivery of the biomaterial despite the fact that the genetic examination was ordered by the court?

If one of the parties evades participation in the examination and does not appear on the date appointed by the experts to take the biomaterial, the court has the right to recognize the fact of kinship or refute it (according to Article 79.3 of the Code of Civil Procedure of the Russian Federation) without conducting an examination. In other words, the court has the right to make a decision in favor of the party that does not evade the examination.

I'm afraid that the maternity hospital may replace the child, can I undergo a DNA test after the birth of the child and confirm that this child is really mine?

Of course. You can order a genetic study and be completely sure that this is your biological child. Biological material can be sent to us by mail.

I doubt the results of the DNA test, what should I do?

In our center we conduct "Review of genetic examinations and studies". We can comment on the genetic study by a third-party organization and, if necessary, draw up a “Specialist’s opinion based on the results of the review of the opinion”.

Is it possible to establish the relationship of various animals (cows, dogs, pigs, etc.) or their identification?

Currently, commercial kits have been developed for genotyping not only humans, but also cows, horses, and dogs. Accordingly, it is possible to establish relationships and identify the corresponding animals. Unfortunately, due to the low demand for these examinations and the limited shelf life of commercial kits, we (and generally in Russia) perform only dog ​​tests.

On the other hand, it is possible to investigate the relationship of two animals on the maternal side by conducting a "Genetic examination of mitochondrial DNA". If, as a result of the examination, the mtDNA genetic profile of the two animals does not match, then this will indicate a different maternal origin of the two individuals, while the coincidence of the genetic profiles will confirm their common maternal relationship.

Similarly, an identification examination can be performed: if, as a result of the examination, the mtDNA genetic profile of two objects does not match, then this indicates two different animals, while the coincidence of genetic profiles indicates that this may be one animal or two animals close on the maternal line.

Thus, mtDNA research has its pluses and minuses. For example, the disadvantages are: 1) it is impossible to prove by mtDNA whether a given object belongs to the same animal; 2) according to mtDNA, it is impossible to establish the relationship between the father and the child. Pros: You can explore any animal kingdom, regardless of whether there are developed commercial kits or not.

Is it possible to say in court that I want to perform a genetic examination in your organization - ANO "Forensic Expert"?

According to Art. 79.2 Code of Civil Procedure of the Russian Federation: The parties, other persons participating in the case, have the right to ask the court to appoint an examination in a specific forensic institution or entrust it to a specific expert; challenge an expert; formulate questions for the expert; get acquainted with the court ruling on the appointment of an examination and with the questions formulated in it; get acquainted with the expert's opinion; to petition the court for the appointment of a repeated, additional, complex or commission examination.

Is it possible to determine the father of a child between monozygotic (identical) twins?

Unfortunately, in such a situation, it is not possible to determine paternity. The genotype of monozygotic twins is completely identical.

In the reserve there are several species of animals (wolves) taken from nature - it is necessary to genetically establish their species affiliation: either related, or other subspecies of the wolf. Is it possible and how much does such a study cost?

It is not difficult to determine the type of animal, having any biomaterial, and even more so assuming its wolf origin. In the same analysis, performed on mitochondrial DNA (mtDNA), it is possible to determine the subspecies of the animal. In this case, we determine the nucleotide sequence of the mtDNA hypervariable region and compare it with the stored sequences in the NCBI database.

With the definition of kinship is a little more complicated. According to mtDNA, kinship can only be established through the maternal line. In this case, identical mtDNA nucleotide sequences indicate descent from one female (mother, grandmother, great-grandmother, etc. only on the maternal line). On the other hand, it would be better to use the loci located on the non-sex chromosomes of nuclear DNA. Fortunately, dogs (Canis lupus familiaris) are so far the only animals (other than humans) for which genetic typing kits have been developed; relationship can be determined. However, since dog genotyping is in low demand in society and commercial kits have a limited shelf life, commercial companies are reluctant to perform such studies.

Moreover, there are two more negative points:

1. population allele frequencies are known only for dogs and it would probably be incorrect to use them for a statistical assessment of the probability of relatedness of wolves.
2. the population must be in Hardy-Weinberg equilibrium, which is not true for isolated populations living in the reserve.

The price of such an analysis, like most genetic studies, is high, due to the high cost of reagents and consumables.

What samples of genetic materials should be taken from an exhumed corpse to determine family relationships using DNA analysis? Is it possible to determine the relationship if more than 3 months have passed?

After three non-winter months, DNA in soft tissues is almost completely destroyed. Therefore, in order to obtain a genetic profile, as a rule, fingernails or toenails (preferably several) and samples of the bone marrow of the femur or other bones are taken.

On the other hand, as practice shows, nuclear DNA often fails to perform a genetic examination of an exhumed corpse. Therefore, it is necessary to investigate mitochondrial DNA (mtDNA). Paternity cannot be established from mtDNA, but maternal kinship can be proven. To do this, it is possible to remove samples of hair, nails and bones during exhumation - phalanges of fingers or toes (2-3 phalanges).

If more than six months have passed since the funeral, then you can not count on an examination by nuclear DNA loci.

Much attention should be paid to the storage of the collected biomaterial from the exhumed corpse. Samples should preferably be stored at -20 and not refrozen. You can place the samples in ethyl alcohol and also put in the refrigerator at -20. If possible, transfer the material to the laboratory as soon as possible.

What organs should be taken for DNA from an exhumed corpse to determine family relationships? If more than 3 months have passed?

Hello, Tatyana. After three non-winter months, DNA in soft tissues is almost completely destroyed. Therefore, in order to obtain a genetic profile, as a rule, fingernails or toenails (preferably several) and samples of the bone marrow of the femur or other bones are taken. On the other hand, as practice shows, nuclear DNA often fails to perform a genetic examination of an exhumed corpse. Therefore, it is necessary to investigate mitochondrial DNA (mtDNA). Paternity cannot be established from mtDNA, but maternal kinship can be proven. To do this, it is possible to remove samples of hair, nails and bones during exhumation - phalanges of fingers or toes (2-3 phalanges). If more than six months have passed since the funeral, then you can not count on an examination by nuclear DNA loci. Much attention should be paid to the storage of the collected biomaterial from the exhumed corpse. Samples should preferably be stored at -20 and not refrozen. You can place the samples in ethyl alcohol and also put in the refrigerator at -20. If possible, transfer the material to the laboratory as soon as possible.

To establish paternity, a genetic examination is necessary, but the judge warned that in some cases the result may be incorrect due to the age of the child (explaining this by the fact that children under the age of one can change the blood type). Can such a factor really affect the outcome of the examination?

For many years, paternity has not been established by blood type. Paternity is established by polymorphic loci of nuclear DNA. In general, DNA testing can be carried out even before the birth of the child, taking fetal material.
In no case should you wait until the child is one year old - you can now conduct an examination to determine paternity. To do this, we will need a few drops of blood, or a cotton swab swab from the inside of the cheeks of all persons participating in the study (mother/child/intended father). You should apply to the court for a genetic test.

Can the combined paternity index be 79.964?

Yes, maybe the paternity index takes any positive value. In this case, the probability of paternity (assuming the probability of paternity before the experience is equal to 50%) is equal to: = 79.964/(79.964+1)=0.9876 or 98.76%.

The son has a second positive blood type, his wife also has a second positive blood type, and their daughters wrote a second negative blood type during the test. Is it possible?

Yes, this is possible! Parents with type 2 blood and Rh positive may have children with type 1 or 2 blood, and either positive or negative. That is, there are four possible options: 1+, 1-, 2+, 2-.

Can biological objects fixed in 4% formalin or 70% alcohol be subjected to genetic examination?

Genetic examination can be done only in relation to objects stored in alcohol. Formalin, on the other hand, strongly destroys the DNA molecule, and in 90% of cases it is not possible to type nuclear loci. On the other hand, mitochondrial DNA (mtDNA) is more resistant to formalin, because it is located in cellular organelles, and our organization was able to conduct an examination on mtDNA. However, it should be borne in mind that the mtDNA examination has its limitations, expressed in the fact that the child receives mitochondria and mtDNA only from the mother, and the establishment of relationship in the framework of the mtDNA study is possible only through the maternal line (see on our website).

A person is endowed with a certain blood type even when he is in the mother's womb. This is the same genetically transmitted trait as the color of the skin, the eye, which remains for life. But still, there are opinions that a change in blood type is quite possible. Let's try to figure out if the blood type can change, or is it just the result of an error when performing the analysis?

Determination of the blood group

A classification according to the ABO system is widespread in the world, within which there are four blood groups that are established using analysis. To carry it out, four sera with antibodies are needed, to which blood is added. The laboratory assistant observes the reaction of red blood cells and the process of their connection. It is on the basis of the results of agglutination that the group affiliation is determined.

The blood groups of the ABO system are the main ones and are used in transfusion. Associated antibodies A and B (immunoglobulins) are formed most often in the first years of life as a result of susceptibility to substances surrounding a person (food, viruses, bacteria).

Blood is a sign that a person is endowed with at birth, and has a certain composition of agglutinogens and agglutinins, genetically encoded. In all respects, it would seem impossible to talk about a change in blood type. So, can a blood type change? Let's figure it out. Still, such cases can occur for a number of specific reasons, which we will list below.

Error in analysis

An erroneously performed analysis to establish the patient's blood type is possible. Despite the simplicity of this procedure, the possibility of an incorrect result can never be excluded, so at some stage in life a person may think that he has a different blood type.

Pregnancy

Pregnancy can also affect the outcome. During this period, the production of erythrocytes increases, and the concentration of agglutinogens decreases so much that the erythrocytes containing them do not combine. Maybe because of this, many are wondering if the blood type changes in life.

Diseases

There are diseases during which the composition of red blood cells may also increase, as was the case in the previous case, and the blood type may change. In addition, certain pathogenic microbes and bacteria release enzymes that change the composition of type A agglutinogens so that they begin to resemble type B agglutinogens.

A blood test in this case will show the second group instead of the third, but the transfusion of group B is in any case impossible, as it will cause incompatible reactions. So the change is temporary. So, thalassemia (Cooley's disease) can reduce the content of antigens. Cancers can also contribute to these changes.

Thus, under certain conditions, the results of the analyzes may temporarily be different, but a change in group membership is in principle impossible. Therefore, the answer to the question of whether the blood type can change will be negative.

Rh factor

In medicine, it is categorically stated that the Rh factor and blood type are constant indicators, inherited properties obtained even at conception and remaining until death. But sometimes events occur that cannot be explained rationally. Opinions about the possibility of changing the blood group and Rhesus are also found. Find out if the blood type and Rh factor are changing.

The Rh factor is a sign that has a genetic origin, and changing it in natural conditions is not feasible. To determine it, you need to check the presence of the Rh antigen on red blood cells. In 85% of humanity, this protein is found, and Rh is positive. The rest, respectively, have a negative indicator.

But there are antigens in the Rh system that are not so immunogenic. Some people who are Rh positive have the ability to produce opposite antibodies, and the expression of the standard Rh antigen is significantly reduced. In this case, positive patients are assigned to the negative group. For example, when donated blood enters a patient, an immune conflict may occur.

It is necessary to determine Rhesus in the process of pregnancy planning in order to timely identify a possible immunological conflict between the fetus and the mother, as a result of which the child may develop a hemolytic disease.

So does blood type change throughout life? There are exceptions to the rules. More on this later.

Unique case

A case of a change in the Rh factor was once recorded by Australian doctors in a girl after a liver transplant. Then all the properties of the immune system changed in her.

During transplantation, this phenomenon is very welcome, since most often the body tries to reject a new organ, which poses a threat to the patient's life. To prevent such a development of events, the patient is prescribed a long-term intake of drugs that suppress the functioning of the immune system. To some extent, this is a non-standard answer to the question of whether the blood type changes in women.

Non-standard scenario

The case with a fifteen-year-old girl did not go according to the standard scenario. When the transplantation was performed, the doctors did all the usual procedures, but after some time the patient developed a disease that rebuilt her immune system. After recovery, an analysis was carried out, as a result of which it turned out that the blood in some incomprehensible way became positive, although it was negative before the liver transplant. As a result, even the immunity readings became the same as those of the donor.

Doctors explain this case by transferring stem cells from a donor organ into the girl's bone marrow. An additional reason could be her young age, due to which there was a small content of leukocytes in the blood. However, such a case is still a single one, more similar phenomena have not been recorded.

Therefore, when asked whether a person’s blood type changes, one must boldly answer: “No.” But the Rh factor can change.

Advanced teaching about changing Rhesus

Researchers at the Brazilian Institute of São João de Meriti, after many tests conducted among patients who underwent spleen and liver transplants, concluded that the protein on red blood cells can change when certain conditions coincide.

Studies show that almost 12% of transplant patients are at risk of changing the sign of the Rh factor, although the blood type is preserved.

Dr. Itar Minas claims that the functioning of the immune system after organ transplantation is significantly rebuilt, especially those that synthesize erythrocyte antigen. He explains this by the fact that during the engraftment of the organ, some hematopoietic functions of the bone marrow are able to take over, and as a result, a change in the polarity of the Rhesus is possible.

The age of the donor and recipient are also significant. Young people are more likely to rearrange antigens than older people. This group of scientists believes that the content of information about protein determinants, which are located in chromosomal alleles and loci (their exact number has not yet been established), also has an influence. It is assumed that some of them may allow the possibility of changing the Rh factor.

So we figured out the question of whether the blood type can change

Any material can be used for analysis, but mouth swabs are standard. Smears from the mouth can be taken independently - instructions. You can also use non-standard materials - blood, nails, earwax.

What is the accuracy of DNA tests?

The DNA test is the most accurate method of establishing paternity. The accuracy in case of a negative answer is 100%. The accuracy in case of a positive answer is 99.9% - 99.99999%. Expert opinion confirming paternity - FATHER– cannot be made with 100% certainty, as there is always a theoretical possibility of the test father having a twin brother with the same genetic profile. The accuracy of the tests offered by our laboratory is the highest available in the world today.

Can paternity be established by blood type?

This method is not a method of establishing paternity, blood types may coincide by chance. Only DNA testing can confirm or disprove paternity. Calculate the blood type and Rh factor of the child

What standards are used to ensure the accuracy of DNA tests?

Our laboratory strictly adheres to the standards of international accreditations AABB, ISO, CLIA and others. Since we use at least 16 genetic markers, the results are usually quite definite - either 0% or 99.9+%. In difficult cases, when 16 markers cannot provide such high accuracy, the laboratory uses up to 33 markers

What is a buccal swab and is it as accurate as blood?

A buccal swab is taken from the mouth with sterile cotton swabs. To take a smear, you need to rub the stick on the inside of the cheek for 10-20 seconds in a circular motion. The result of a DNA test will be as accurate as a blood test, since the DNA in all cells is the same.

Can regular ear swabs be used for swabs?

For smears, it is desirable to use sterile sticks, it is most convenient to purchase a set for taking smears from our centers. However, you can also use ordinary cotton swabs - open a new package before taking the material and remove the cotton wrap from one side of the stick. Use 2-4 sticks for each participant and put in paper envelopes. See instructions for details.

How long can a smear be stored if I take it at home and bring it to you not immediately?

The set with the taken genetic material can be stored for a long time - several months, however, we recommend that you do not delay its transfer for analysis, transfer it within 7-10 days, since the probability of successful DNA extraction decreases over time.

Is it possible to send me a smear kit and results without anyone knowing about it?

We understand the sensitivity of the issue of establishing paternity. The set and results will be transferred to you in the most convenient way for you. Order a set

Can a paternity test be done without the mother?

Yes, usually the test is done only for the father and the child. Mother's consent is not required. However, if the mother is also involved in the test, the test may be more accurate in some cases.

What if I want to do a DNA test on another child or another father?

Additional family members can be included in the test - another father, child, for an additional fee, the cost of such a test will be cheaper than performing two separate tests.

At what age can a child be tested for paternity?

Even a newborn can be a participant in a DNA test. Taking a saliva swab with a cotton swab is a painless and non-traumatic procedure. If the baby is breastfeeding, it is necessary that at least an hour has passed since the last feeding.

What happens to the samples after the test?

We destroy samples as soon as the test is done and the results are in. Test participants' data is archived.

How will I receive the test results?

The results can be obtained from our centres, or they can be sent by post, e-mail and communicated by phone. You choose the method of issuing results when ordering a test.

How to interpret test results?

In the vast majority of cases, the conclusion contains an unambiguous result. The alleged father is either "excluded" or "not excluded" as the biological father. Each of the identifying loci is analyzed separately, a paternity index is calculated from it, then the individual indices are combined to calculate a "combined paternity index". The higher the combined index, the higher the likelihood of paternity.

What does the result of a DNA paternity test look like?

The result of a DNA paternity test is a letterhead document with a laboratory seal that contains a conclusion about the likelihood of paternity. In the case of a negative result, paternity is excluded, its probability is 0%. In the case of a positive result, paternity is not excluded, its probability is 99.9+%. In addition to the conclusion, the document contains the genetic passports of the test persons, that is, information about the DNA structure that is unique for each person.

What is the combined paternity index?

The combined paternity index is a number that represents the likelihood of paternity. The number is calculated based on how common the genetic information found in test subjects is in your race population. The combined paternity index can generate a 99.999% probability of paternity, and even higher. For example, a KPI of 9,999,987 means that the chances of the alleged father being the biological father are 9,999,987 to one.

Is it possible to use the conclusion in court instances?

The conclusion you receive from performing the analysis for your personal use can be used as a basis for filing a claim. Such analysis is done without identifying individuals. Analysis for the court is done with the identification of the participants, only it will have legal force.

Are the results confidential?

Your results are strictly confidential and are issued only to you personally, to the postal or email address you specified. Any information on the analysis is reported only to the customer's phone number specified in the order form.

Can the test be done anonymously?

You can, you can specify any names when ordering a test.

Do I need a referral from a doctor or court to order a DNA test?

No, you don't need any referrals, it's your right to know the truth.

Is it possible to do a DNA test if for some reason it is not possible to take a buccal swab?

Why are you offering such a low price for a DNA paternity test?

Our laboratory is the largest in the world and thanks to the latest automated equipment, we do more tests per unit of time. So, our goal is to attract as many customers as possible, and not to earn a lot on one. At the same time, the quality of the test is at the level of world standards.

Can a paternity test be done before the baby is born?

Yes, we can do a prenatal paternity test. The analysis that we offer is completely safe for the fetus, paternity is determined by the venous blood of the mother and the alleged father. Such an analysis is possible if the gestational age is at least 9 complete obstetric weeks.

Does DNA change after a blood transfusion?

DNA does not change after a blood transfusion. In the case of blood sampling within 2-3 weeks after a blood transfusion, there is a small chance that a mixed DNA profile will be obtained (an undesirable situation). But this is not a problem when taking material from the oral cavity (oral swab - as in our case), or if more time has passed since the transfusion. All donated blood is cleared by this time.

Can you be sure about the result of a DNA paternity test if the next of kin of the alleged father (father, son, brother) can also be the biological father of the child?

In this case, you must inform us that there is such a situation. If it is not possible to test both putative fathers, we will run an extended analysis and calculate the chances that the next of kin may be the biological father. In any case, you can be sure of the result of the analysis.

What happens if I take the material incorrectly myself? Will I need to pay for the analysis again?

In this case, you will have to resubmit the material. You don't need to pay anything.

Why such a fast DNA analysis? In other clinics, it is done for about a month.

Since we do a large number of analyses, material is sent to the laboratory several times a week. Delivery of samples - 2 working days. The analysis itself takes 2-5 working days. If the analysis is urgent, it is sent immediately and runs with the highest priority.

The alleged father does not want to do a DNA test, how do I determine paternity?

For analysis, you can use the material of the father's relatives - parents, children, brothers and sisters. An analysis of grandparents and grandchildren is as accurate as a paternity test.

The alleged father is far away, in another country. How can I do a DNA test?

You can take the material yourself anywhere in the world and send it to us for analysis. It is stored for a long time, several months. You can also use the collection services of any doctors, including representative offices of our laboratory in 168 countries.

Human mutations: history and modernity

The renaissance that NASA is experiencing is mirrored in what happens in our bodies. In the depths of our DNA, we are renewed and become completely different. All over the world there are genetic changes in human DNA. What many scientists call mutation has already happened, and whether you like it or not, there are at least three new human races - three very different types of races to meet the needs of the new humanity. Huge changes are taking place within us, and hardly any of us are aware of it. The process of transformation is quiet, but it becomes louder and louder with the first breath of every newborn baby.

DNA changes are rare, but they do happen. One of the most well-documented cases involves human blood. From the moment of its inception until the relatively recent past, mankind had only one type of blood. Neza-

regardless of how the skin looked - black, yellow, red, white, brown - the blood was the same for everyone. All people had type O blood in their veins, and all killed animals for their livelihood. Hunting was the main way of obtaining food as early as 15 thousand years ago, until a huge comet crashed into the Earth on the coast of Atlantis.

What happened? Most of the world's population, with the exception of the inhabitants of Atlantis, has ceased to migrate from place to place in the process of hunting animals; we have become farmers. And accordingly, our diet has changed. We began to eat vegetables and grains in combinations that the human body had never known before. Our body responded to a change in diet by mutating DNA and creating a new, previously unknown blood type - type A. In addition to transforming the blood, other DNA changes occurred that affected the acids and enzymes of the stomach and other functions of the body in order to assimilate new foods. Some scientists believe that this mutation may also have been affected by climate change.

Since then, the transformation of human blood has occurred two more times, each time in response to changing dietary habits and likely climatic factors. Blood types B and AB appeared. Now there are four types of blood, but is this the limit?

By the end of the twentieth century, food from all over the world became available to almost every one of us. Mankind began to consume food brought from all over the globe. In the developed world, you can go to almost any big store and buy whatever you want, from where you want - papaya from Mexico, avocados from California, olives from Greece, vodka from Russia, and so on. You can come to any American city and taste Chinese, Mexican, Italian, Japanese, American, German and so on. Will a new blood type emerge to accommodate this unprecedented food mix?

As you can see, DNA mutation occurs in association with seemingly harmless changes in diet and climate. The changes now sweeping the Earth are astounding by any measure. They are so huge that you can expect a response from the human genetics, and, no doubt, this reaction has already begun.

Today, changes have taken place in the human genetic apparatus, and they have such far-reaching consequences for the future of mankind that I simply have to tell about them. Most of the people in whose bodies DNA changes are observed are children.

They can be divided into three distinct categories, each with extremely different, but equally astonishing, new abilities. There may be more than three categories, but this is all that has been found so far. In my opinion, such children are leading us into a new future, and our life will be radically different from the life that humanity has led on Earth for the past few million years. As I said earlier, in order to complete the karma of the third dimension, these children probably changed the nature of the transition to the fourth dimension in such a way as to enable everyone people to make the transition. However, in any case, even regardless of the transition, the new genetic qualities will change humanity forever.

In 1974, a genetically modified child was discovered in China for the first time. The little boy could "see" with his ears. Yes, yes, he could see with his ears just as you can see with your eyes - in fact, even better. Do you think it's impossible? Read on, a surprise awaits you that will turn all the foundations of your life upside down.

However, I'm getting ahead of myself. Let's start with the USA, with a whole new race of kids. These are the so-called indigo children.