1.) In rare cases, individuals do not produce an A-, B-, or O-type oligosacchari

Question

1.) In rare cases, individuals do not produce an A-, B-, or O-type oligosaccharide at all. Can these individuals receive type A, B, or O blood transfusions? Can they donate blood to others?

Please give detail!

The ABO Blood Group System

The carbohydrates on the surface of red blood cells and other human cells form 15 different blood group systems. The best known and one of the clinically important carbohydrate-classification schemes is the ABO blood group system, which has been known for about a century. Biochemically, the ABO system involves the oligosaccharides attached to sphingolipids and proteins on red blood cells and other cells.

In individuals with type A blood, the oligosaccharide has a terminal N-acetylated galactose group. In type B individuals, the terminal sugar is galactose. Neither of these groups appears in the oligosaccharides of type O individuals.

Blood groups are genetically determined: Type A and B individuals have slightly different versions of the gene for a glycosyltransferase that adds the final monosaccharide residue to the oligosaccharide. Type O individuals have a mutation such that they lack the enzyme entirely and therefore produce an oligosaccharide without the final residue.

Type A individuals develop antibodies that recognize and cross-link red blood cells bearing the type B oligosaccharide. Type B individuals develop antibodies to the type A oligosaccharide. Therefore, a transfusion of type B blood cannot be given to a type A individual, and vice versa. Individuals with type AB blood bear both types of oligosaccharides and therefore do not develop antibodies to either type. They can receive transfusions of either type A or type B blood. Type O individuals develop both anti-A and anti-B antibodies. If they receive a transfusion of type A, type B, or type AB blood, their antibodies will react with the transfused cells, which causes them to lyse or to clump together and block blood vessels. On the other hand, type O individuals are universal donors: Type A, B, or AB individuals can safely receive type O blood (these individuals do not develop antibodies to the O-type oligosaccharide because it occurs naturally in these individuals as a precursor of the A-type and B-type oligosaccharides).

1.) In rare cases, individuals do not produce an A-, B-, or O-type oligosaccharide at all. Can these individuals receive type A, B, or O blood transfusions? Can they donate blood to others?

Please give detail!

Explanation / Answer

ANS ) The red blood cells seemed to lack all of the abo blood organization antigens and to have an extra antigen that became formerly unknown.People with the uncommon bombay phenotype (hh) do no longer specific h antigen (also called substance h), the antigen that is present in blood institution o. as a result, they cannot make a antigen (additionally known as substance a) or b antigen (substance b) on their purple blood cells, anything alleles they may have of the a and b blood-institution genes, because a antigen and b antigen are made from h antigen. for that reason human beings who have bombay phenotype can donate red blood cells to any member of the abo blood institution machine (unless a few other blood element gene, consisting of rhesus, is incompatible), however they cannot receive blood from any member of the abo blood institution machine (which usually contains one or extra of a and b and h antigens), however only from different people who've bombay phenotype. Receiving blood which includes an antigen which has in no way been within the patient's own blood causes an immune response because of the immune machine of a hypothetical receiver producing immunoglobulins no longer simplest against antigen a and b, but also in opposition to h antigen. the most commonplace immunoglobulins synthesized are igm and igg (and this appears to have a very crucial role inside the low frequency of hemolytic disease of the new child among non-bombay offspring of bombay mothers).It is very crucial, on the way to keep away from any complications at some point of a blood transfusion, to hit upon bombay phenotype people, due to the fact the standard checks for abo blood institution gadget would show them as group o. seeing that anti-h immunoglobulins can activate the complement cascade, it will result in the lysis of purple blood cells whilst they are nevertheless in the move, upsetting an acute hemolytic transfusion response. this, of course, can not be averted until the lab technologist that is worried is aware of the lifestyles of the bombay blood institution and has the approach to test for it.

Bosynthesis of the h, a and b antigens includes a chain of enzymes (glycosyl transferases) that transfer monosaccharides. the resulting antigens are oligosaccharide chains, which might be connected to lipids and proteins which can be anchored inside the pink blood mobile membrane. the characteristic of the h antigen, apart from being an intermediate substrate within the synthesis of abo blood group antigens, isn't always acknowledged, even though it is able to be concerned in cellular adhesion. luckily, people who lack the h antigen do no longer suffer from deleterious results, and being h-deficient is only an issue in the event that they want a blood transfusion, due to the fact they would want blood with out h.

The specificity of the h antigen is determined by means of the sequence of oligosaccharides. extra particularly, the minimal requirement for h antigenicity is the terminal disaccharide fucose-galactose, wherein the fucose has an alpha(1-2)linkage. this antigen is produced by a specific fucosyl transferase that catalyzes the very last step in the synthesis of the molecule. depending upon someone's abo blood type, the h antigen is transformed into either the a antigen, b antigen, or both. if someone has group o blood, the h antigen stays unmodified. therefore, the h antigen is present more in blood kind o and less in blood type AB.

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