Rare Blood Types
Interesting Information About Rare Blood Types
Most Americans today are wondering if they have rare blood types because unlike other countries, this is not information that is usually made available to you unless you need to know it or you request it. While a majority of people fall into just a few categories, there are others who have such a rare type of blood that finding a donor when needed can be very difficult.
What Is A Blood Type?
A blood type is simply a blood classification that is based on the absence or presence of inherited antigenic substances that are found on the surface of your red blood cells. Depending on the group system of the blood, these antigens can be proteins, glycoproteins, carbohydrates or glycolipids. Many of these surface antigens stem from one closely linked gene.
Blood types are always inherited and are contributions from both parents. Interestingly, pregnant women are able to carry a fetus that has a different type of blood than what she has and she is able to create antibodies to protect her and the baby against the variations. On occasion, small amounts of immunoglobulin can cause hemolysis after it crosses the placenta. This can result in the newborn having hemolytic disease or low fetal blood counts. This can range from being mild to severe. Newborns with rare blood types are often affected more severely than those with common blood types.
Frequency Of Blood Types
To get an idea of which the rare blood types are, it is helpful to understand how often they occur. These are figures based on North America:
- O Positive – 1 in 3 people = 37.4%
- O Negative – 1 in 15 people = 6.6%
- A Positive – 1 in 3 people = 35.7%
- A Negative – 1 in 16 people = 6.3%
- B Positive – 1 in 12 people = 8.5%
- B Negative – 1 in 67 people = 1.5%
- AB Positive – 1 in 29 people = 3.4%
- AB Negative –1 in 167 people = .6%
Blood Cell Compatibility
Regardless if you have common or rare blood types, it is important to donate because there never seems to be enough blood and you may be the person who needs it one day. Below are compatibility listings for blood type groups.
- Blood Group O – These individuals have neither A or B surface antigens however their blood serum does contain anti-B antibodies and anti-A antibodies. Therefore, while these individuals are able to donate blood to A,B,O or AB groups, they can only receive blood from an individual with O blood. O negative blood always sees a dangerous shortage.
- Blood Group B – These individuals have B surface antigens and their blood serum has 1Gm antibodies. These individuals can donate to AB or B groups but can only receive blood from B or O groups.
- Blood Group A – Individuals with these blood types have A surface antigens with 1Gm antibodies in their blood serum against the B antigens. They can donate to A or AB and receive from A or O groups.
- Blood Group AB – These people have A as well as B antigens but their blood contains no antibodies against A or B. Therefore, while they are only able to donate to another AB match, they can actually receive blood from any blood group donor.
There are also some other extremely rare blood types that are often named after the patient who they were discovered in being ABO, MNS, P, Rh, Lutheran, Kell, Lewis, Duffy, Kidd, Diego, Cartwright, XG, Scianna, Dombrook, Colton, Landsteimer-Weiner, Chido/Rodgers, Hh/Bombay, Kx, Gerbich, Cromer, Knops, Indian, Ok, Ralph, JMH, li, Globoside, GIL and Rh-associated glycoprotein.
Transfusion medicine works with blood banks to provide blood and other products to patients who need them. Blood bank experts are responsible for testing recipients and donors to ensure that there are no acute hemolytic reactions.
Rare blood types always cause supply concerns for both hospitals and blood banks. Since some blood types are more common in certain areas of the world, there are always added risks involved when individuals travel to other counties if they have rare blood types. If there is an emergency, it is often difficult to track down a suitable donor in a timely manor.