What is H-deficient?
What is H-deficient?
H-deficient is a very rare blood type possessed by only one in a million, mainly because the blood is exceptionally prized by vampires. Humans with this type of blood are described by vampires as smelling “very good” and/or “delicious”, suggesting it also tastes better than other types of blood.
What is H antigen in blood?
Also known as substance H, H antigen is a precursor to each of the ABO blood group antigens, apparently present in all people except those with the Bombay Blood phenotype (see hh blood group) Histocompatibility antigen, a major factor in graft rejection.
What is the rare blood type that lacks the H antigen?
The Bombay blood group
The Bombay blood group is a rare blood group, phenotypes of this group lacking H antigen on the red cell membrane and have anti-H in the serum. It fails to express any A, B or H antigen on their red cells or other tissues.
Who has H antigen?
Immunology: All humans have H antigen on RBCs. However, some people, particularly those who are A blood type, have another blood group antigen, called A antigen, since they have the A allele that encodes for the enzyme glycosyltransferase that catalyzes the binding of N-acetylgalactosamine to the H antigen.
Is H deficient blood good?
There is no ill effect with being H deficient, but if a blood transfusion is ever needed, people with this blood type can receive blood only from other donors who are also H deficient. (A transfusion of “normal” group O blood can trigger a severe transfusion reaction.)
What is anti H antibody?
Anti-H antibody is a type of anti-red blood cell (RBC) antibody that agglutinates with H antigen, which is universally present on human RBCs. The most widely known problem related to the anti-H antibody is the potentially lethal hemolytic transfusion reaction seen in individuals with the Bombay O blood type [1,2,3].
What if H antigen too is absent?
If anyone lacks Antigen H, it does not mean he or she suffers from poor immunity or may be more prone to diseases. Their counts for haemoglobin, platelets, white blood cells and red blood cells are similar to the count of others based on their health index.
What is H gene?
The H gene encodes an enzyme that is required in the expression of the H antigen on the surface of red blood cells. Translation of the active allele, H, of the FUT1 gene results in formation of the enzyme known as α-1,2-fucosyltransferase (H is also known as FUT1 because the gene product is a FUcosyl Transferase).
Is there an H blood type?
The rare, Bombay blood group was first discovered in Mumbai (then Bombay) in 1952 by Dr Y M Bhende. Each red blood cell has antigen over its surface, which helps determine which group it belongs to. The Bombay blood group, also called hh, is deficient in expressing antigen H, meaning the RBC has no antigen H.
What are the side effects of being H deficient?
There is no ill effect with being H deficient, but if a blood transfusion is ever needed, people with this blood type can receive blood only from other donors who are also H deficient. (A transfusion of “normal” group O blood can trigger a severe transfusion reaction.)
What percentage of the population has H antigen?
Frequency of the H antigen. Present on 99.9% of RBCs in all populations. H deficiency is rare: it is found in 1 of 8,000 in Taiwan, 1 of 10,000 in India, and 1 per million in Europe (1).
What is the meaning of Rh deficiency syndrome?
Summary Summary. The Rh deficiency syndrome, also known as Rh-null syndrome, is a blood disorder where people have red blood cells (RBCs) lacking all Rh antigens. The Rh antigens maintain the integrity of the RBC membrane and therefore, RBCs which lack Rh antigens have an abnormal shape.
What is the nomenclature of H antigens?
Nomenclature Number of H antigens: 1 ISBT symbol: H ISBT number: 018 Gene symbol: FUT1 Gene name: Fucosyltransferase 1 Basic biochemistry The biosynthesis of the H antigen and the A and B antigens involves a series of enzymes (glycosyltransferases) that transfer monosaccharides.