Do you know your blood type? Chances are, you’re familiar with ABO blood typing, which categorizes blood types based on the presence or absence of certain antigens on the surface of red blood cells. However, there’s another important marker that helps determine blood type: the Rhesus (Rh) factor. In this article, we’ll take a deep dive into what the Rhesus blood type is, how it’s inherited, and what it means for your health.
What is the Rhesus blood type?
The Rhesus (Rh) blood type is a classification system that indicates whether or not a person has a specific antigen called Rh factor on their red blood cells. If you have the Rh factor, you’re considered Rh positive (Rh+). If you don’t have the Rh factor, you’re Rh negative (Rh-). About 85% of people are Rh positive, while the remaining 15% are Rh negative.
How is the Rhesus blood type inherited?
The Rhesus blood type, like the ABO blood type, is inherited from your parents. If both of your parents are Rh positive, you have a 93% chance of being Rh positive as well. If one parent is Rh positive and one is Rh negative, there’s a 50% chance you’ll be Rh positive and a 50% chance you’ll be Rh negative. If both of your parents are Rh negative, you’ll be Rh negative as well.
The genetics of Rh blood type
The Rh factor is determined by a single gene on chromosome 1. This gene can come in two different versions, or alleles: RhD and RhD-.RhD is dominant, meaning that if you have at least one copy of the RhD allele, you’ll be Rh positive. RhD- is recessive, meaning that you have to inherit two copies of the RhD- allele to be Rh negative.
| Parents | Possible Rh factor of offspring |
|---|---|
| Rh+ and Rh+ | Rh+ (93%) or Rh- (7%) |
| Rh+ and Rh- | Rh+ (50%) or Rh- (50%) |
| Rh- and Rh- | Rh- (100%) |
What are the implications of the Rhesus blood type?
Rhesus incompatibility during pregnancy
One of the most important implications of the Rhesus blood type is that it can cause problems during pregnancy. If a woman who is Rh negative becomes pregnant with a baby who is Rh positive, there’s a risk that her immune system will recognize the baby’s blood cells as foreign and produce antibodies to destroy them. This can lead to a condition called hemolytic disease of the newborn, which can cause anemia, jaundice, brain damage, or even death in severe cases.
To prevent this from happening, women who are Rh negative are typically given a shot of Rh immune globulin at around 28 weeks of pregnancy, which helps prevent their immune system from attacking the baby’s blood cells. If the baby is Rh positive, the mother will receive another shot of Rh immune globulin within 72 hours of delivering the baby.
Rhesus incompatibility during blood transfusions
In addition to pregnancy complications, Rhesus incompatibility can also cause problems during blood transfusions. If a person who is Rh negative receives donated blood that is Rh positive, their immune system may produce antibodies against the Rh factor, which can cause a transfusion reaction. Symptoms of a transfusion reaction can include fever, chills, chest pain, and difficulty breathing.
How is the Rhesus blood type tested?
The Rhesus blood type is typically determined through a blood test. The test looks for the presence or absence of the Rh factor on a person’s red blood cells. If the Rh factor is present, the person is Rh positive. If it’s absent, they’re Rh negative.
Conclusion
The Rhesus blood type is an important marker of human blood that can have significant implications for health. Understanding your own blood type, as well as the blood types of potential donors or recipients, is essential for ensuring safe and effective medical care.
FAQs
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What is the difference between ABO blood typing and Rhesus blood typing?
ABO blood typing categorizes blood types based on the presence or absence of certain antigens on the surface of red blood cells, while Rhesus blood typing determines whether or not a person has the Rh factor on their red blood cells.
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Can a person’s blood type change over time?
No, a person’s blood type is determined by their genetics and remains the same throughout their life.
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Is the Rhesus blood type more important than the ABO blood type?
Both ABO and Rhesus blood types are important for medical purposes, and medical professionals will typically test for both to determine a person’s blood type.
References
- Mayo Clinic. (2021). Rh factor blood test. https://www.mayoclinic.org/tests-procedures/rh-factor/about/pac-20394960
- NHS. (2021). Blood types. https://www.nhs.uk/conditions/blood-groups/
- The American Red Cross. (2021). Types of Blood Donations. https://www.redcrossblood.org/donate-blood/blood-types/types-of-blood-donations.html