If the child’s blood type does not match one of the parents, this can become a real family tragedy, since the baby’s father will suspect that the baby is not his own. In fact, this phenomenon may be due to a rare genetic mutation that occurs in one in 10 million people in the European race! In science, this phenomenon is called the “Bombay phenomenon”. In biology classes we were taught that a child inherits the blood type of one of the parents, but it turns out that this is not always the case. It happens that, for example, parents with the first and second blood groups give birth to a baby with the third or fourth. How is this possible?

For the first time, genetics was faced with a situation when a baby was found to have a blood type that could not be inherited from its parents in 1952. The male father had blood group I, the female mother had blood group II, and their child was born with blood group III. According to this combination is impossible. The doctor who observed the couple suggested that the child’s father did not have the first blood type, but an imitation of it, which arose due to some genetic changes. That is, the gene structure has changed, and therefore the blood characteristics have changed.

This also applies to proteins responsible for the formation of blood groups. There are 2 of them - agglutinogens A and B, located on the membrane of erythrocytes. Inherited from parents, these antigens create a combination that determines one of the four blood groups.

The Bombay phenomenon is based on recessive epistasis. In simple words, under the influence of a mutation, the blood group has the characteristics of I (0), since it does not contain agglutinogens, but in fact it is not such.

How can you tell if you have the Bombay Phenomenon? Unlike the first blood group, when it does not have agglutinogens A and B on red blood cells, but there are agglutinins A and B in the blood serum, in individuals with the Bombay phenomenon, agglutinins are determined by the inherited blood group. Although there will be no agglutinogen B on the child’s red blood cells (reminiscent of blood group I (0), only agglutinin A will circulate in the serum. This will distinguish blood with the Bombay phenomenon from normal blood, because normally people with group I have both agglutinins - A and B.

If the need for blood transfusion arises, patients with the Bombay phenomenon can only be transfused with exactly the same blood. Finding it, for obvious reasons, is unrealistic, so people with this phenomenon, as a rule, save their own material at blood transfusion stations in order to use it if necessary.

If you are the owner of such rare blood, be sure to tell your spouse about it when you get married, and when you decide to have offspring, consult a geneticist. In most cases, people with the Bombay phenomenon give birth to children with a normal blood type, but one that does not comply with the rules of inheritance recognized by science.

Photos from open sources

From school we know that there are four main blood types. The first three are common, but the fourth is rare. The groups are classified according to the content of agglutinogens in the blood, which form antibodies. However, few people know that there is also a fifth group, called the “Bombay phenomenon”.

To understand what we are talking about, you should remember the content of antigens in the blood. So, the second group contains antigen A, the third contains antigen B, the fourth contains antigens A and B, and the first group does not contain these elements, but it contains antigen H - this is a substance that takes part in the construction of other antigens. In the fifth group there is neither A, nor B, nor H.

Inheritance

Blood type determines heredity. If parents have the third and second groups, then their children can be born with any of the four groups, if the parents have the first group, then the children will only have blood of the first group. However, there are cases when parents give birth to children with an unusual, fifth group or Bombay phenomenon. This blood does not contain antigens A and B, which is why it is often confused with the first group. But in Bombay blood there is no antigen H, contained in the first group. If a child turns out to have the Bombay phenomenon, then it will not be possible to accurately determine paternity, since there is not a single antigen in the blood that his parents have.

History of discovery

The discovery of an unusual blood type was made in 1952, in India, in the Bombay area. During malaria, massive blood tests were carried out. During the examinations, several people were identified whose blood did not belong to any of the four known groups, since it did not contain antigens. These cases were called the "Bombay phenomenon". Later, information about such blood began to appear all over the world, and in the world, for every 250,000 people, one has a fifth type. In India, this figure is higher - one per 7,600 people.

According to scientists, the emergence of a new group in India is due to the fact that consanguineous marriages are allowed in this country. According to Indian laws, procreation within a caste allows one to preserve one’s position in society and family wealth.

What's next

After the discovery of the Bombay phenomenon, scientists at the University of Vermont made a statement that there are other rare blood types. The latest discoveries are named Langereis and Junior. These species contain completely unknown proteins responsible for blood type.

The uniqueness of the 5th group

The most common and oldest is the first group. It arose during the time of the Neanderthals - it is more than 40 thousand years old. Almost half of the world's population has the first blood group.

The second group appeared about 15 thousand years ago. It is also not considered rare, but according to various sources, about 35% of people are carriers of it. Most often, the second group is found in Japan and Western Europe.

The third group is less common. Its carriers are about 15% of the population. Most people with this group are found in Eastern Europe.

Until recently, the fourth group was considered the newest group. About five thousand years have passed since its appearance. It occurs in 5% of the world's population.

The Bombay phenomenon (blood group V) is considered the newest, as it was discovered several decades ago. There are only 0.001% of people on the entire planet with such a group.

Formation of the phenomenon

The classification of blood groups is based on the content of antigens. This information applies to blood transfusions. It is believed that the H antigen contained in the first group is the “progenitor” of all existing groups, since it is a kind of building material from which antigens A and B emerged.

The formation of the chemical composition of blood occurs in utero and depends on the blood groups of the parents. And here geneticists can tell which possible groups a baby may be born with by carrying out simple calculations. Sometimes deviations from the usual norm do occur, and then children are born who exhibit recessive epistasis (Bombay phenomenon). Their blood does not contain antigens A, B, H. This is the uniqueness of the fifth blood group.

People with the fifth group

These people live the same way as millions of others, with other groups. Although there are some difficulties for them:

1. It's difficult to find a donor. If a blood transfusion is necessary, only the fifth group can be used. However, Bombay blood can be used for all groups without exception, and there are no consequences.
2. Paternity cannot be established. If you need to do a DNA paternity test, it will not give any results, since the child will not have the antigens that his parents have.

There is a family in the USA in which two children were born with the Bombay phenomenon, and also with the A-H type. Such blood was detected once in the Czech Republic in 1961. There are no donors for children in the world, and transfusions from other groups are fatal for them. Because of this feature, the eldest child became his own donor, and the same thing awaits his sister.

Biochemistry

It is generally accepted that there are three types of genes responsible for blood groups: A, B and 0. Each person has two genes - one gets from the mother, and the second from the father. Based on this, there are six gene variations that determine blood type:

1. The first group is characterized by the presence of 00 genes.
2. For the second group - AA and A0.
3. The third contains antigens 0B and BB.
4. In the fourth - AB.

Carbohydrates are located on the surface of red blood cells, they are also antigens 0 or antigens H. Under the influence of certain enzymes, antigen H is encoded into A. The same thing happens when antigen H is encoded into B. Gene 0 does not produce any encoding of the enzyme. When there is no synthesis of agglutinogens on the surface of erythrocytes, i.e., there is no original H antigen on the surface, then this blood is considered Bombay. Its peculiarity is that in the absence of the H antigen, or “source code,” there is nothing to convert into other antigens. In other cases, various antigens are found on the surface of red blood cells: the first group is characterized by the absence of antigens, but the presence of H, the second - A, the third - B, the fourth - AB. People with the fifth group do not have any genes on the surface of their red blood cells, and they don’t even have H, which is responsible for coding, even if there are enzymes that are encoded - it is impossible to convert H into another gene, because this source H does not exist.

The original H antigen is encoded by a gene called H. It looks like this: H is the gene that encodes the H antigen, h is a recessive gene in which the H antigen is not formed. As a result, when conducting a genetic analysis of the possible inheritance of blood groups, parents may have children with different groups. For example, parents with the fourth group cannot have children with the first group, but if one of the parents has the Bombay phenomenon, then they can have children with any group, even with the first.

Conclusion

Over the course of many millions of years, evolution has been taking place, and not only of our planet. All living beings change. Evolution has not abandoned blood either. This liquid not only allows us to live, but also protects us from the negative effects of the environment, viruses and infections, neutralizing them and preventing them from penetrating vital systems and organs. Similar discoveries made by scientists decades ago in the form of the Bombay phenomenon, as well as other types of blood groups, remain a mystery. And it is unknown how many secrets that have not yet been revealed by scientists are kept in the blood of people around the world. Maybe after some time it will become known about another phenomenal discovery of a new group, which will be very new, unique, and the people with it will have incredible abilities.

A person with a blood type known as the Bombay phenomenon is a universal donor: his blood can be transfused to people with any blood type. However, people with this rare blood type cannot accept blood of any other type. Why?

There are four blood groups (first, second, third and fourth): the classification of blood groups is based on the presence or absence of an antigenic substance that appears on the surface of blood cells. Both parents influence and determine the child's blood type.

Knowing the blood type, a couple can predict the blood type of their unborn child using the Punnett grid. For example, if the mother has the third blood group, and the father has the first blood group, then most likely their child will have the first blood group.

However, there are rare cases when a couple gives birth to a child with the first blood group, even if they do not have the genes for the first blood group. If this occurs, the child most likely has Bombay phenomenon, which was first discovered in three people in Bombay (now Mumbai) in India in 1952 by Dr. Bhende and his colleagues. The main characteristic of red blood cells in the Bombay phenomenon is the absence of h-antigen in them.

Rare blood type

The h-antigen is located on the surface of red blood cells and is the precursor of antigens A and B. The A-allele is necessary for the production of transferase enzymes, which convert the h-antigen into the A-antigen. In the same way, the B allele is necessary for the production of transferase enzymes for the transition of h-antigen to B-antigen. In blood type O, the h-antigen cannot be converted because transferase enzymes are not produced. It is worth noting that antigen conversion occurs by adding complex carbohydrates produced by transferase enzymes to the h-antigen.

Bombay phenomenon

A person with Bombay phenomenon inherits a recessive allele for the h antigen from each parent. He carries the homozygous recessive genotype (hh) instead of the homozygous dominant (HH) and heterozygous (Hh) genotypes found in all four blood types. As a result, the h-antigen does not appear on the surface of blood cells, so antigens A and B are not formed. The h-allele is the result of a mutation in the H-gene (FUT1), which affects the manifestation of the h-antigen in erythrocytes. Scientists have found that people with Bombay phenomenon are homozygous (hh) for the T725G mutation (leucine 242 changes to arginine) in the FUT1 coding region. This mutation produces an inactivated enzyme that is unable to form the h-antigen.

Antibody production

People with Bombay phenomenon produce protective antibodies against the H, A, and B antigens. Because their blood produces antibodies against the H, A, and B antigens, they can only receive blood from donors with the same phenomenon. Transfusion of blood from the other four groups can be fatal. There have been cases in the past where patients with supposedly O blood type died during transfusion because doctors did not test for the Bombay phenomenon.

Since the Bombay phenomenon is , it is very difficult for patients with this blood type to find donors. The probability of having a donor with the Bombay phenomenon is 1 in 250,000 people. India has the highest number of people with the Bombay phenomenon: 1 case in 7,600 people. Geneticists are convinced that the large number of people with the Bombay phenomenon in India is associated with consanguineous marriages between members of the same caste. Consanguineous marriage in the upper caste allows you to maintain your position in society and protect your wealth.

August 15th, 2017

Who doesn’t know that people have four main blood groups. The first, second and third are quite common, the fourth is not so widespread. This classification is based on the content of so-called agglutinogens in the blood - antigens responsible for the formation of antibodies.

Blood type is most often determined by heredity, for example, if the parents have the second and third groups, the child can have any of the four, if the father and mother have the first group, their children will also have the first, and if, say, the parents have the fourth and the first, the child will have either the second or the third.

However, in some cases, children are born with a blood type that, according to the rules of inheritance, they cannot have - this phenomenon is called the Bombay phenomenon, or Bombay blood.

Within the ABO/Rhesus blood group systems that are used to classify most blood types, there are several rare blood types. The rarest is AB-, this blood type is observed in less than one percent of the world's population. Types B- and O- are also very rare, each accounting for less than 5% of the world's population. However, in addition to these two main ones, there are more than 30 generally accepted blood typing systems, including many rare types, some of which are observed in a very small group of people.

There are three types of genes responsible for blood group - A, B, and 0 (three alleles).

Every person has two blood type genes - one received from the mother (A, B, or 0), and one received from the father (A, B, or 0).

There are 6 possible combinations:

On the surface of our red blood cells there are carbohydrates - “H antigens”, also known as “0 antigens”. (On the surface of red blood cells there are glycoproteins that have antigenic properties. They are called agglutinogens.)

Bombay phenomenon

H - gene encoding antigen H

h - recessive gene, H antigen is not formed

This mutation was first discovered in Bombay, hence the name. In India, it occurs in one person in 10,000, in Taiwan - in one in 8,000. In Europe, hh is very rare - in one person in two hundred thousand (0.0005%).

An example of the Bombay phenomenon No. 1: if one parent has the first blood group, and the other has the second, then the child cannot have the fourth group, because neither parent has the B gene necessary for group 4.

And now the Bombay phenomenon:

And now the Bombay phenomenon

Cis position A and B

In a person with blood type 4, during crossing over, an error (chromosomal mutation) may occur when both genes A and B appear on one chromosome, but nothing on the other chromosome. Accordingly, the gametes of such an AB will turn out strange: one will contain AB, and the other will have nothing.

And now the mutation:

The probability of having children shaded in gray is, of course, less - 0.001%, as agreed, and the remaining 99.999% falls on groups 2 and 3. But still, these fractions of a percent “should be taken into account during genetic counseling and forensic medical examination.”

The everyday life of a person with unique blood does not differ from its other classifications, with the exception of several factors:
· a serious problem is transfusion; only the same blood can be used for these purposes, while it is a universal donor and is suitable for everyone;
· impossibility of establishing paternity; if it happens that DNA testing is necessary, it will not give results, since the child does not have the antigens that his parents have.

Interesting fact! In the USA, Massachusetts, there lives a family where two children have the Bombay phenomenon, only they also have an A-H type, such blood was diagnosed once in the Czech Republic in 1961. They cannot be donors for each other, since they have different rhesus. factor, and transfusion of any other group is naturally impossible. The eldest child reached adulthood and became a donor for himself as a last resort, the same fate awaits his younger sister when she turns 18

And something else interesting on medical topics: I talked about it in detail here and here. Or maybe someone is interested or, for example, well-known to everyone

As you know, there are four main blood groups in humans. The first, second and third are quite common, the fourth is not so widespread. This classification is based on the content of so-called agglutinogens in the blood - antigens responsible for the formation of antibodies. The second blood group contains antigen A, the third contains antigen B, the fourth contains both of these antigens, and the first contains no antigens A and B, but there is a “primary” antigen H, which, among other things, serves as a “building material” for the production of antigens contained in the second, third and fourth blood groups.

Blood type is most often determined by heredity, for example, if the parents have the second and third groups, the child can have any of the four, if the father and mother have the first group, their children will also have the first, and if, say, the parents have the fourth and the first, the child will have either the second or the third. However, in some cases, children are born with a blood type that, according to the rules of inheritance, they cannot have - this phenomenon is called the Bombay phenomenon, or Bombay blood.

By the way, the Japanese often ask what their blood type is when they first meet a person. This is somewhat surprising to foreigners, but the Japanese ask this question for a reason, but because they want to determine the main character traits of this person.

Let's understand blood groups and check character according to this parameter

In truth, there are no special statistics or scientific grounds to consider such a definition of character reliable. However, since it is often talked about on TV and many books are sold, the number of people interested in it is increasing in Japan, Korea and Vietnam.

In the Japanese “horoscope” for the owner of each blood type - A, B, O and AB, there is a description of character.
Now this phenomenon has gained extraordinary popularity; publishing books and websites on this topic can make a good business.

A (II) They are honest, capable of working in a group, very diligent, hide their thoughts and feelings; worry about what others think of them, think clearly, don't like to lose, worry about little things, rely on facts rather than emotions; patient, prone to pessimism;

B (III) Active, self-centered, completely immersed in work, hobbies, favorite things; not interested in fame and power, have a keen sense of justice, are emotional, have a good sense of humor, their mood often changes, they do not pay attention to rules, they do not pay attention to other people;

O (I) Cheerful, loved by people, romantic, often complain, easily moved, stubborn, often help people, if something unpleasant happens, the mood quickly deteriorates; do not hide their feelings, love people with a character different from theirs; optimistic;

AB (IV) Serious, delicate, inquisitive, expressing one’s own feelings causes difficulties, pure, manic, have a keen sense of justice, mysterious, often doubt people, take promises seriously, have a very complex character.

*************************************************

Within the ABO/Rhesus blood group systems that are used to classify most blood types, there are several rare blood types. The rarest is AB-, this blood type is observed in less than one percent of the world's population. Types B- and O- are also very rare, each accounting for less than 5% of the world's population. However, in addition to these two main ones, there are more than 30 generally accepted blood typing systems, including many rare types, some of which are observed in a very small group of people.

Blood type is determined by the presence of certain antigens in the blood. Antigens A and B are very common, making it easier to classify people based on which antigen they have, whereas people with type O blood have neither antigen. A positive or negative sign after the group means the presence or absence of the Rh factor. At the same time, in addition to antigens A and B, other antigens may be present, and these antigens may react with the blood of certain donors. For example, someone may have type A+ blood and not have another antigen in their blood, indicating the likelihood of an adverse reaction with type A+ donated blood containing that antigen.

Bombay blood does not have antigens A and B, so it is often confused with the first group, but it also does not contain antigen H, which can become a problem, for example, when determining paternity - after all, the child does not have a single antigen in his blood that he has. him from his parents.

A rare blood type does not cause its owner any problems, except for one thing - if he suddenly needs a blood transfusion, then only the same Bombay blood can be used, and this blood can be transfused to a person with any group without any consequences.

The first information about this phenomenon appeared in 1952, when the Indian doctor Vhend, conducting blood tests in a family of patients, received an unexpected result: the father had blood group 1, the mother had blood group II, and the son had blood group III. He described this case in the largest medical journal, The Lancet. Subsequently, some doctors encountered similar cases, but could not explain them. And only at the end of the 20th century the answer was found: it turned out that in such cases the body of one of the parents mimics (fake) one blood group, while in fact it has another; two genes are involved in the formation of the blood group: one determines the group blood, the second encodes the production of an enzyme that allows this group to be realized. For most people this scheme works, but in rare cases the second gene is missing, and therefore the enzyme is missing. Then the following picture is observed: a person has, for example. Blood group III, but it cannot be realized, and the analysis reveals II. Such a parent passes on his genes to the child - hence the child’s “inexplicable” blood type. There are few carriers of such mimicry - less than 1% of the Earth's population.

The Bombay phenomenon was discovered in India, where, according to statistics, 0.01% of the population have “special” blood; in Europe, Bombay blood is even less common - approximately 0.0001% of the population.

And now a little more detail:

There are three types of genes responsible for blood group - A, B, and 0 (three alleles).

Every person has two blood type genes - one received from the mother (A, B, or 0), and one received from the father (A, B, or 0).

There are 6 possible combinations:

How it works (from the point of view of cell biochemistry)

On the surface of our red blood cells there are carbohydrates - “H antigens”, also known as “0 antigens”. (On the surface of red blood cells there are glycoproteins that have antigenic properties. They are called agglutinogens.)

Gene A encodes an enzyme that converts some of the H antigens into A antigens. (Gene A encodes a specific glycosyltransferase that adds an N-acetyl-D-galactosamine residue to an agglutinogen, resulting in agglutinogen A).

Gene B encodes an enzyme that converts some of the H antigens into B antigens (Gene B encodes a specific glycosyltransferase that adds a D-galactose residue to the agglutinogen, resulting in agglutinogen B).

Gene 0 does not code for any enzyme.

Depending on the genotype, carbohydrate vegetation on the surface of red blood cells will look like this:

For example, let’s cross parents with groups 1 and 4 and see why they cannot have a child with group 1.

(Because a child with type 1 (00) should receive a 0 from each parent, but a parent with blood type 4 (AB) does not have a 0.)

Bombay phenomenon

It occurs when a person does not produce the “original” antigen H on his red blood cells. In this case, the person will have neither antigens A nor antigens B, even if the necessary enzymes are present. Well, great and powerful enzymes will come to convert H into A... oops! but there’s nothing to transform, there’s no one!

The original H antigen is encoded by a gene, which is unsurprisingly designated H.
H – gene encoding antigen H
h – recessive gene, H antigen is not formed

Example: a person with the AA genotype must have blood group 2. But if he is AAHh, then his blood type will be the first, because there is nothing to make antigen A from.

This mutation was first discovered in Bombay, hence the name. In India, it occurs in one person in 10,000, in Taiwan - in one in 8,000. In Europe, hh is very rare - in one person in two hundred thousand (0.0005%).

An example of the Bombay phenomenon No. 1: if one parent has the first blood group, and the other has the second, then the child cannot have the fourth group, because neither of the parents has the B gene necessary for group 4.

And now the Bombay phenomenon:

The trick is that the first parent, despite its BB genes, does not have B antigens, because there is nothing to make them from. Therefore, despite the genetic third group, from the point of view of blood transfusion he has the first group.

An example of the Bombay phenomenon No. 2. If both parents have group 4, then they cannot have a child of group 1.

And now the Bombay phenomenon

As we see, with the Bombay phenomenon, parents with group 4 can still get a child with group 1.

Cis position A and B

In a person with blood group 4, during crossing over, an error (chromosomal mutation) may occur, when both genes A and B will appear on one chromosome, and there will be nothing on the other chromosome. Accordingly, the gametes of such an AB will turn out strange: one will contain AB, and the other will have nothing.

Of course, chromosomes containing AB and chromosomes containing nothing at all will be rejected by natural selection, because they will have difficulty conjugating with normal, non-mutant chromosomes. In addition, AAV and ABB children may experience a gene imbalance (impaired viability, death of the embryo). The probability of encountering a cis-AB mutation is estimated at approximately 0.001% (0.012% cis-AB relative to all AB).

Example of cis-AV. If one parent has group 4, and the other has group 1, then they cannot have children of either group 1 or 4.

And now the mutation:

The probability of having children shaded in gray is, of course, less - 0.001%, as agreed, and the remaining 99.999% falls on groups 2 and 3. But still, these fractions of a percent “should be taken into account during genetic counseling and forensic medical examination.”

In medicine, four blood groups are described in detail. They all differ in the location of agglutinins on the surface of red blood cells. This property is encoded genetically using proteins A, B and H. Bombay syndrome is very rarely recorded in people. This anomaly is characterized by the presence of the fifth blood group. Patients with the phenomenon lack proteins that are normally detected. The peculiarity is formed at the stage of intrauterine development, that is, it is of a genetic nature. This characteristic of the main body fluid is rare and does not exceed one in ten million cases.

5 blood group or the history of the Bombay phenomenon

This feature was discovered and described not so long ago, in 1952. The first cases of lack of antigens A, B and H in humans were registered in India. It is here that the percentage of the population with the anomaly is the highest and amounts to 1 case in 7600. The discovery of Bombay syndrome, that is, a rare blood type, occurred as a result of studying fluid samples using mass spectrometry. Tests were carried out due to an epidemic in the country of a disease such as malaria. The defect was named after an Indian city.

Theories of the origin of Bombay blood

Presumably, the anomaly formed against the background of frequent consanguineous marriages. They are common in India due to social customs. Incest not only led to an increase in the prevalence of genetic diseases, but to the emergence of Bombay syndrome. This feature is currently found in only 0.0001% of the planet's population. A rare characteristic of the main fluid in the human body may remain unrecognized due to the imperfections of modern diagnostic methods.

Development mechanism

In total, four blood groups are described in detail in medicine. This division is based on the location of agglutinins on the surface of red blood cells. Outwardly, these characteristics do not appear in any way. However, they need to be known in order to carry out blood transfusion from one person to another. If the groups do not match, reactions occur that can lead to the death of the patient.

This phenomenon is completely determined by the chromosomal set of the parents, that is, it is hereditary. The laying occurs even at the stage of intrauterine development. For example, if the father has the first blood group, and the mother has the fourth, then the child will have the second or third. This characteristic is due to combinations of antigens A, B and H. Bombay syndrome occurs against the background of recessive epistasis - non-allelic interaction. This is what causes the absence of blood proteins.

Features of life and problems with paternity

The presence of this anomaly does not affect human health in any way. A child or adult may not be aware of the presence of a unique feature of the organism. Difficulties arise only if the patient needs a blood transfusion. Such people are universal donors. This means that their liquid is suitable for everyone. However, when determining Bombay syndrome, the patient will need the same unique group. Otherwise, the patient will face incompatibility, which will mean a threat to life and health.

Another problem is confirming paternity. The procedure is difficult for people with this blood type. Determination of family relationships is based on the detection of corresponding proteins that are not detected when the patient has Bombay syndrome. Therefore, in doubtful situations, more difficult genetic tests will be required.

Modern medicine has not described any pathologies associated with a rare blood group. Perhaps this feature is caused by the low prevalence of Bombay syndrome. It is assumed that many patients with the phenomenon are unaware of its presence. However, a case of detection of a rare hemolytic disease in a newborn baby, whose mother had a fifth blood group, has been described. The diagnosis was confirmed based on the results of antibody screening, lectin studies, and determination of the location of agglutinins on the surface of the red blood cells of the mother and child.

The pathology diagnosed in the patient is accompanied by life-threatening processes. These features are associated with incompatibility between the blood of the parent and the fetus. In this case, two patients suffer from the disease at once. In the described case, the mother's hematocrit was only 11%, which did not allow her to become a donor for the child.

A big problem in such cases is the lack of this rare type of physiological fluid in blood banks. This is primarily due to the low prevalence of Bombay syndrome. Another difficulty is the fact that patients may not be aware of the feature. Moreover, according to available data, many people with the fifth group willingly agree to be donors because they realize the importance of creating a blood bank. In case of hemolytic disease of newborns against the background of diagnosis of Bombay syndrome in the mother, cases of which are rare, there is also the possibility of conservative treatment without the use of blood transfusion. The effectiveness of such therapy depends on the severity of pathological changes in the body of the mother and child.

The significance of unique blood

The anomaly is considered poorly understood. Therefore, it is too early to talk about the impact of this feature on the health of the planet’s population and medicine. It is undeniable that the occurrence of Bombay syndrome complicates the already difficult procedure of blood transfusion. The presence of blood group 5 in a person puts life and health at risk when the need for transfusion arises. At the same time, a number of scientists are inclined to believe that such an evolutionary event may have a beneficial effect in the future, since this structure of biological fluid is considered perfect in comparison with other common options.

From school we know that there are four main blood types. The first three are common, but the fourth is rare. The groups are classified according to the content of agglutinogens in the blood, which form antibodies. However, few people know that there is also a fifth group, called the “Bombay phenomenon”.

To understand what we are talking about, you should remember the content of antigens in the blood. So, the second group contains antigen A, the third contains antigen B, the fourth contains antigens A and B, and the first group does not contain these elements, but it contains antigen H - this is a substance that takes part in the construction of other antigens. In the fifth group there is neither A, nor B, nor H.

Inheritance

Blood type determines heredity. If parents have the third and second groups, then their children can be born with any of the four groups, if the parents have the first group, then the children will only have blood of the first group. However, there are cases when parents give birth to children with an unusual, fifth group or Bombay phenomenon. This blood does not contain antigens A and B, which is why it is often confused with the first group. But in Bombay blood there is no antigen H, contained in the first group. If a child turns out to have the Bombay phenomenon, then it will not be possible to accurately determine paternity, since there is not a single antigen in the blood that his parents have.

History of discovery

The discovery of an unusual blood type was made in 1952, in India, in the Bombay area. During malaria, massive blood tests were carried out. During the examinations, several people were identified whose blood did not belong to any of the four known groups, since it did not contain antigens. These cases were called the "Bombay phenomenon". Later, information about such blood began to appear all over the world, and in the world, for every 250,000 people, one has a fifth type. In India, this figure is higher - one per 7,600 people.

According to scientists, the emergence of a new group in India is due to the fact that consanguineous marriages are allowed in this country. According to Indian laws, procreation within a caste allows one to preserve one’s position in society and family wealth.

What's next

After the discovery of the Bombay phenomenon, scientists at the University of Vermont made a statement that there are other rare blood types. The latest discoveries are named Langereis and Junior. These species contain completely unknown proteins responsible for blood type.

The uniqueness of the 5th group

The most common and oldest is the first group. It arose during the time of the Neanderthals - it is more than 40 thousand years old. Almost half of the world's population has the first blood group.

The second group appeared about 15 thousand years ago. It is also not considered rare, but according to various sources, about 35% of people are carriers of it. Most often, the second group is found in Japan and Western Europe.

The third group is less common. Its carriers are about 15% of the population. Most people with this group are found in Eastern Europe.

Until recently, the fourth group was considered the newest group. About five thousand years have passed since its appearance. It occurs in 5% of the world's population.

The Bombay phenomenon (blood group V) is considered the newest, as it was discovered several decades ago. There are only 0.001% of people on the entire planet with such a group.

Formation of the phenomenon

The classification of blood groups is based on the content of antigens. This information applies to blood transfusions. It is believed that the H antigen contained in the first group is the “progenitor” of all existing groups, since it is a kind of building material from which antigens A and B emerged.

The formation of the chemical composition of blood occurs in utero and depends on the blood groups of the parents. And here geneticists can tell which possible groups a baby may be born with by carrying out simple calculations. Sometimes deviations from the usual norm do occur, and then children are born who exhibit recessive epistasis (Bombay phenomenon). Their blood does not contain antigens A, B, H. This is the uniqueness of the fifth blood group.

People with the fifth group

These people live the same way as millions of others, with other groups. Although there are some difficulties for them:

1. It's difficult to find a donor. If a blood transfusion is necessary, only the fifth group can be used. However, Bombay blood can be used for all groups without exception, and there are no consequences.
2. Paternity cannot be established. If you need to do a DNA paternity test, it will not give any results, since the child will not have the antigens that his parents have.

There is a family in the USA in which two children were born with the Bombay phenomenon, and also with the A-H type. Such blood was detected once in the Czech Republic in 1961. There are no donors for children in the world, and transfusions from other groups are fatal for them. Because of this feature, the eldest child became his own donor, and the same thing awaits his sister.

Biochemistry

It is generally accepted that there are three types of genes responsible for blood groups: A, B and 0. Each person has two genes - one gets from the mother, and the second from the father. Based on this, there are six gene variations that determine blood type:

1. The first group is characterized by the presence of 00 genes.
2. For the second group - AA and A0.
3. The third contains antigens 0B and BB.
4. In the fourth - AB.

Carbohydrates are located on the surface of red blood cells, they are also antigens 0 or antigens H. Under the influence of certain enzymes, antigen H is encoded into A. The same thing happens when antigen H is encoded into B. Gene 0 does not produce any encoding of the enzyme. When there is no synthesis of agglutinogens on the surface of erythrocytes, i.e., there is no original H antigen on the surface, then this blood is considered Bombay. Its peculiarity is that in the absence of the H antigen, or “source code,” there is nothing to convert into other antigens. In other cases, various antigens are found on the surface of red blood cells: the first group is characterized by the absence of antigens, but the presence of H, the second - A, the third - B, the fourth - AB. People with the fifth group do not have any genes on the surface of their red blood cells, and they don’t even have H, which is responsible for coding, even if there are enzymes that are encoded - it is impossible to convert H into another gene, because this source H does not exist.

The original H antigen is encoded by a gene called H. It looks like this: H is the gene that encodes the H antigen, h is a recessive gene in which the H antigen is not formed. As a result, when conducting a genetic analysis of the possible inheritance of blood groups, parents may have children with different groups. For example, parents with the fourth group cannot have children with the first group, but if one of the parents has the Bombay phenomenon, then they can have children with any group, even with the first.

Conclusion

Over the course of many millions of years, evolution has been taking place, and not only of our planet. All living beings change. Evolution has not abandoned blood either. This liquid not only allows us to live, but also protects us from the negative effects of the environment, viruses and infections, neutralizing them and preventing them from penetrating vital systems and organs. Similar discoveries made by scientists decades ago in the form of the Bombay phenomenon, as well as other types of blood groups, remain a mystery. And it is unknown how many secrets that have not yet been revealed by scientists are kept in the blood of people around the world. Maybe after some time it will become known about another phenomenal discovery of a new group, which will be very new, unique, and the people with it will have incredible abilities.

As you know, there are four main blood groups in humans. The first, second and third are quite common, the fourth is not so widespread. This classification is based on the content of so-called agglutinogens in the blood - antigens responsible for the formation of antibodies. The second blood group contains antigen A, the third contains antigen B, the fourth contains both of these antigens, and the first contains no antigens A and B, but there is a “primary” antigen H, which, among other things, serves as a “building material” for the production of antigens contained in the second, third and fourth blood groups.

Blood type is most often determined by heredity, for example, if the parents have the second and third groups, the child can have any of the four, if the father and mother have the first group, their children will also have the first, and if, say, the parents have the fourth and the first, the child will have either the second or the third. However, in some cases, children are born with a blood type that, according to the rules of inheritance, they cannot have - this phenomenon is called the Bombay phenomenon, or Bombay blood.

Bombay blood does not have antigens A and B, so it is often confused with the first group, but it also does not contain antigen H, which can become a problem, for example, when determining paternity - after all, the child does not have a single antigen in his blood that he has. him from his parents.

The Bombay phenomenon was discovered in 1952 in India, where, according to statistics, 0.01% of the population have “special” blood; in Europe, Bombay blood is even less common - approximately 0.0001% of the population.

A rare blood type does not cause its owner any problems, except for one thing - if he suddenly needs a blood transfusion, then only the same Bombay blood can be used, and this blood can be transfused to a person with any group without any consequences.

6 Important Facts Nobody Tells You About Surgical Weight Loss

Is it possible to “cleanse the body of toxins”?

The biggest scientific discoveries of 2014

Experiment: a man drinks 10 cans of cola a day to prove its harm

How to quickly lose weight for the New Year: taking emergency measures

5 most unimaginable human genetic pathologies

5 folk remedies for treating colds - does it work or not?

In medicine, four blood groups are described in detail. They all differ in the location of agglutinins on the surface of red blood cells. This property is encoded genetically using proteins A, B and H. Bombay syndrome is very rarely recorded in people. This anomaly is characterized by the presence of the fifth blood group. Patients with the phenomenon lack proteins that are normally detected. The peculiarity is formed at the stage of intrauterine development, that is, it is of a genetic nature. This characteristic of the main body fluid is rare and does not exceed one in ten million cases.

5 blood group or the history of the Bombay phenomenon

This feature was discovered and described not so long ago, in 1952. The first cases of lack of antigens A, B and H in humans were registered in India. It is here that the percentage of the population with the anomaly is the highest and amounts to 1 case in 7600. The discovery of Bombay syndrome, that is, a rare blood type, occurred as a result of studying fluid samples using mass spectrometry. Tests were carried out due to an epidemic in the country of a disease such as malaria. The defect was named after an Indian city.

Theories of the origin of Bombay blood

Presumably, the anomaly formed against the background of frequent consanguineous marriages. They are common in India due to social customs. Incest not only led to an increase in the prevalence of genetic diseases, but to the emergence of Bombay syndrome. This feature is currently found in only 0.0001% of the planet's population. A rare characteristic of the main fluid in the human body may remain unrecognized due to the imperfections of modern diagnostic methods.

Development mechanism

In total, four blood groups are described in detail in medicine. This division is based on the location of agglutinins on the surface of red blood cells. Outwardly, these characteristics do not appear in any way. However, they need to be known in order to carry out blood transfusion from one person to another. If the groups do not match, reactions occur that can lead to the death of the patient.

This phenomenon is completely determined by the chromosomal set of the parents, that is, it is hereditary. The laying occurs even at the stage of intrauterine development. For example, if the father has the first blood group, and the mother has the fourth, then the child will have the second or third. This characteristic is due to combinations of antigens A, B and H. Bombay syndrome occurs against the background of recessive epistasis - non-allelic interaction. This is what causes the absence of blood proteins.

Features of life and problems with paternity

The presence of this anomaly does not affect human health in any way. A child or adult may not be aware of the presence of a unique feature of the organism. Difficulties arise only if the patient needs a blood transfusion. Such people are universal donors. This means that their liquid is suitable for everyone. However, when determining Bombay syndrome, the patient will need the same unique group. Otherwise, the patient will face incompatibility, which will mean a threat to life and health.

Another problem is confirming paternity. The procedure is difficult for people with this blood type. Determination of family relationships is based on the detection of corresponding proteins that are not detected when the patient has Bombay syndrome. Therefore, in doubtful situations, more difficult genetic tests will be required.

Modern medicine has not described any pathologies associated with a rare blood group. Perhaps this feature is caused by the low prevalence of Bombay syndrome. It is assumed that many patients with the phenomenon are unaware of its presence. However, a case of detection of a rare hemolytic disease in a newborn baby, whose mother had a fifth blood group, has been described. The diagnosis was confirmed based on the results of antibody screening, lectin studies, and determination of the location of agglutinins on the surface of the red blood cells of the mother and child.

The pathology diagnosed in the patient is accompanied by life-threatening processes. These features are associated with incompatibility between the blood of the parent and the fetus. In this case, two patients suffer from the disease at once. In the described case, the mother's hematocrit was only 11%, which did not allow her to become a donor for the child.

A big problem in such cases is the lack of this rare type of physiological fluid in blood banks. This is primarily due to the low prevalence of Bombay syndrome. Another difficulty is the fact that patients may not be aware of the feature. Moreover, according to available data, many people with the fifth group willingly agree to be donors because they realize the importance of creating a blood bank. In case of hemolytic disease of newborns against the background of diagnosis of Bombay syndrome in the mother, cases of which are rare, there is also the possibility of conservative treatment without the use of blood transfusion. The effectiveness of such therapy depends on the severity of pathological changes in the body of the mother and child.

The significance of unique blood

The anomaly is considered poorly understood. Therefore, it is too early to talk about the impact of this feature on the health of the planet’s population and medicine. It is undeniable that the occurrence of Bombay syndrome complicates the already difficult procedure of blood transfusion. The presence of blood group 5 in a person puts life and health at risk when the need for transfusion arises. At the same time, a number of scientists are inclined to believe that such an evolutionary event may have a beneficial effect in the future, since this structure of biological fluid is considered perfect in comparison with other common options.