June 10th, 2014

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.

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 in the blood certain antigens. 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. 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 blood type A+ and lack another antigen in their blood, indicating the likelihood of an adverse reaction with donated blood group A+ containing this 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 similar 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 a blood group: one determines the blood group, 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 “inexplicable” blood type in the child. 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:

genes	group
00	1
0A	2
AA
0V	3
BB
AB	4

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:

genes	specific antigens on the surface of red blood cells		letter designation of the group
00	-	1	0
A0	A	2	A
AA
B0	IN	3	IN
BB
AB	A and B	4	AB

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 parent 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.

Parent AB (4 group)	Parent AB (group 4)
	A	IN
A	AA (2nd group)	AB (4 group)
IN	AB (4 group)	BB (3rd group)

And now the Bombay phenomenon

Parent ABHh (4 group)	Parent ABHh (4th group)
	AH	Ah	B.H.	Bh
A.H.	AAHH (2nd group)	AAHh (2nd group)	ABHH (4 group)	ABHh (4 group)
Ah	AAHH (2nd group)	Ahh (1 group)	ABHh (4 group)	АBhh (1 group)
B.H.	ABHH (4 group)	ABHh (4 group)	BBHH (3rd group)	BBHh (3rd group)
Bh	ABHh (4 group)	ABhh (1 group)	ABHh (4 group)	BBhh (1 group)

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.

What other parents have to offer	Mutant parent
	AB	-
0	AB0 (4 group)	0- (1 group)
A	AAV (4 group)	A- (2nd group)
IN	ABB (4 group)	IN- (3rd group)

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:

Parent 00 (1 group)	AB mutant parent (4 group)
	AB	-	A	IN
0	AB0 (4 group)	0- (1 group)	A0 (2nd group)	B0 (3rd group)

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.”

sources

http://www.factroom.ru/facts/54527,

http://www.vitaminov.net/rus-catalog_zabolevaniy-896802656-0-23906.html

http://ru.wikipedia.org/wiki/%D0%93%D1%80%D1%83%D0%BF%D0%BF%D1%8B_%D0%BA%D1%80%D0%BE%D0 %B2%D0%B8_%D1%87%D0%B5%D0%BB%D0%BE%D0%B2%D0%B5%D0%BA%D0%B0

http://bio-faq.ru/zzz/zzz014.html

And something else interesting on medical topics: here I talked in detail and here. Or maybe someone is interested or, for example, well-known to everyone The original article is on the website InfoGlaz.rf Link to the article from which this copy was made -

	Inheritance of blood groups.
	Bombay phenomenon...
	There are three types of genes responsible for blood group - A, B, 0
	(three alleles).
	Every person has two blood group genes - one,
	received from the mother (A, B, or 0), and the second, received from
	father (A, B, or 0).
	There are 6 possible combinations:

How does it work (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 H antigens into A antigens.(Gene A encodes a specific glycosyltransferase that adds the residueN-acetyl-D-galactosamineto an agglutinogen, resulting in agglutinogen A).

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

Gene 0 does not code for any enzyme.

	Inheritance of blood groups.
	Bombay phenomenon...
	Depending on		genotype,
	carbohydrate vegetation on
	surfaces	red blood cells
	will look like this:

Inheritance of blood groups. Bombay phenomenon...

For example, let's cross parents with groups 1 and 4 and see why they havethere cannot be a child with 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.)

Inheritance of blood groups. Bombay phenomenon...

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.

Original		H is encoded by a gene that		denoted by
			encoding
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%).

Inheritance of blood groups. Bombay phenomenon...

An example of the Bombay phenomenon at work:if one parent has the first blood group, and the other has the second, then the child can't have fourth group, because none of them

parents do not have the B gene required for group 4.

ParentParent A0 (group 2)
(1 group)									Bombay
								Parent	Parent
								(1 group)	(2nd group)
The trick is that the first parent, despite
on its BB genes, has no B antigens,
because there is nothing to make them from. Therefore, no
looking at the genetic third group, with									(4 group)
blood transfusion point of view group y
		him first.

Polymerism…

Polymerism is the interaction of non-allelic multiple genes that unidirectionally influence the development of the same trait; The degree of manifestation of a trait depends on the number of genes. Polymer genes are designated by the same letters, and alleles of the same locus have the same subscript.

Polymer interaction of non-allelic genes can be

cumulative and non-cumulative.

With cumulative (accumulative) polymerization, the degree of manifestation of the trait depends on the total action of several genes. The more dominant gene alleles, the more pronounced a particular trait is. Segregation in F2 according to the phenotype during dihybrid crossing occurs in the ratio 1: 4: 6: 4: 1, and in general corresponds to the third, fifth (with dihybrid crossing), seventh (with trihybrid crossing), etc. lines in Pascal's triangle.

Polymerism…

With non-cumulative polymerization, the signmanifests itself in the presence of at least one of the dominant alleles of polymer genes. The number of dominant alleles does not affect the degree of expression of the trait. Segregation in F2 according to phenotype during dihybrid crossing is 15:1.

Polymer example- inheritance of skin color in humans, which depends (to a first approximation) on four genes with a cumulative effect.

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 the European race in one person in 10 million! 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 group, 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 four groups blood.

The Bombay phenomenon is based on recessive epistasis. Speaking 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

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.

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 “inexplicable” blood type in the child. 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:

genes	group
00	1
0A	2
AA
0V	3
BB
AB	4

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:

genes	specific antigens on the surface of red blood cells		letter designation of the group
00	-	1	0
A0	A	2	A
AA
B0	IN	3	IN
BB
AB	A and B	4	AB

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 parent 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.

Parent AB (4 group)	Parent AB (group 4)
	A	IN
A	AA (2nd group)	AB (4 group)
IN	AB (4 group)	BB (3rd group)

And now the Bombay phenomenon

Parent ABHh (4 group)	Parent ABHh (4th group)
	AH	Ah	B.H.	Bh
A.H.	AAHH (2nd group)	AAHh (2nd group)	ABHH (4 group)	ABHh (4 group)
Ah	AAHH (2nd group)	Ahh (1 group)	ABHh (4 group)	АBhh (1 group)
B.H.	ABHH (4 group)	ABHh (4 group)	BBHH (3rd group)	BBHh (3rd group)
Bh	ABHh (4 group)	ABhh (1 group)	ABHh (4 group)	BBhh (1 group)

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 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.

What other parents have to offer	Mutant parent
	AB	-
0	AB0 (4 group)	0- (1 group)
A	AAV (4 group)	A- (2nd group)
IN	ABB (4 group)	IN- (3rd group)

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:

Parent 00 (1 group)	AB mutant parent (4 group)
	AB	-	A	IN
0	AB0 (4 group)	0- (1 group)	A0 (2nd group)	B0 (3rd group)

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.”

How do they live with unusual blood?

The everyday life of a person with unique blood does not differ from its other classifications, with the exception of several factors:
· transfusion is a serious problem; only the same blood can be used for these purposes, and it is universal donor and suits 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 at the same time A-H type, such blood was diagnosed once in the Czech Republic in 1961. They cannot be donors to each other, since they have a different Rh 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

10.04.2015 13.10.2015

Blood is a unique liquid in the human body; it continuously circulates through the vessels, supplies oxygen, as well as necessary components. internal organs. Everyone knows that there are four of its groups, I, II, III, IV, but not everyone knows about the existence of another, extremely rare, exceptional group called the Bombay phenomenon.

Undiscovered Blood, a Discovery Story

The discovery of the phenomenon occurred in 1952, in India (the city of Mumbai, formerly Bombay, where the name originated), by the scientist Bhende. The discovery was made during research into mass malaria, after three people lacked the necessary antigens that determine which type the blood belongs to. Cases of occurrence are unique, the number of people with the Bombay phenomenon in the world is one per two hundred and fifty thousand population, only in India this figure is higher, amounting to 1 case per 7,600 people.

Interesting fact! Scientists believe that the emergence unknown blood in India it is associated with frequent marriages with members of one’s own family. According to the laws of the country, procreation within the circle of one, higher caste allows you to preserve wealth and your position in society.

Recently, a sensational statement was made by employees of the University of Vermont that there are also types of rare blood, their names are Junior and Langereis. They were discovered by mass spectrometry, as a result of which two completely new proteins were identified. Previously, science knew about 30 proteins responsible for blood group, and now there are 32 of them, which allowed scientists to announce their discovery. Experts believe that this discovery is a new step in the fight against cancer and will allow the development of new technology oncology treatment.

What is unique?

· The first group is considered the most widespread, it arose during the time of the Neanderthals and has been known for more than 40 thousand years, almost half of its carriers on earth;

· The second has been known for more than 15 thousand years, it is also not rare, according to various sources, its carriers are about 35%, the most people with this type in Japan and Western Europe;

· the third, slightly less common than the first two, approximately the same amount is known about it as about the second, the largest concentration of people with this species is found in Eastern Europe, its total carriers are about 15%;

· the fourth, the newest, no more than a thousand years have passed since its formation, it arose as a result of the merger of I and III, only 5%, and according to some data, even 3% of the world's population have this important red liquid flowing through their vessels.

Now imagine, if group IV is considered young and rare, what can we say about the Bombay group, which is just over 60 years old from its discovery and is found in 0.001% of people on the planet; of course, its uniqueness is undeniable.

How is the phenomenon formed?

Classification into groups is based on the content of antigens, for example, the second contains antigen A, the third contains antigen B, the fourth contains both of them, and in the first they are absent, but there is an initial antigen H and all the others arise from it, it is considered a kind of “building material” for A and B.

Pawning chemical composition blood in a child occurs in utero and depends on what kind of blood it is in the parents; it is heredity that becomes the fundamental factor. But there are rare exceptions to the rules that cannot be explained genetically. This is the emergence of the Bombay phenomenon, it lies in the fact that born children have a type of blood that a priori they cannot have. It does not have antigens A and B, so it can be confused with the first group, but it also does not have the H component, this is its uniqueness.

How do they live with unusual blood?

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.

· In the body of an average adult man, the blood volume is 5-6 liters;

· June fourteenth is considered world donor day, it is dedicated to the birthday of Karl Landsteiner, he was the first to classify blood into groups;

· it is believed that if the icon begins to bleed, there will be trouble; there are people who claim to have observed this process before the terrorist attack of September 11, 2001 and the beginning of World War II. Also, written sources speak of a bleeding icon before St. Bartholomew's Night;

· in the middle of the 20th century, a relationship was established between the tendency to certain diseases and blood type, for example, those with the second group are more susceptible to leukemia and malaria, those with the first group are more susceptible to ruptures of ligaments, tendons and peptic ulcers;

· the diagnosis of cancer is heard more often than others in the third group, less often than others in the first;

· there is a person who lives without a pulse, his uniqueness lies in the fact that instead of the heart that was removed, he has a device installed for blood circulation, it continues to function fully, but there is no pulse even when an ECG is performed;

· in Japan they are sure that the character and fate of a person depends on what type of blood he was born with.

The liquid, which has evolved over millions of years in order to give us the opportunity to live, contains many mysteries and secrets. It protects us from exposure environment, from various viruses and infections, neutralizing them, preventing them from penetrating into the vital important organs. But how many more secrets, in addition to the Bombay phenomenon, as well as the Junior and Langereis groups, remain to be revealed to scientists and told to the whole world.