You probably know of the Blood type A, B, AB and O, but do you know there is another blood type that is so rare that less than 50 people in the world have it?
As a matter of fact, scientists call it “golden”—but despite the pretty name it has, it can actually be dangerous for the people that have it.
This rare blood type is another reason why you should know which group you belong to. And while having golden blood might sound exciting, this incredibly rare type has the potential to be deadly for people who have it.
Each of the common blood types—A, B, AB, and O—comes in negative and positive versions. Of these eight main categories, O positive is the most common. AB negative is identified as the rarest blood type.
While that sounds pretty rare, AB negative has nothing on the rarest blood type of all—one that fewer than 50 people in the entire world have—which is why scientists have nicknamed it “golden blood.” The type, whose scientific name is Rhnull blood, was discovered in 1961.
Since then, there have been a total of 43 reported cases. Its rarity and unique properties combine to make it potentially dangerous, should someone with this type ever need a blood transfusion.
The reason why it is important for you to know what blood group you have is that your red blood cells have receptors called antigens. If you receive a transfusion, your immune system will only accept the antigens that match your blood type.
If you happen to get the wrong type—and a mismatched set of antigens—your immune system will attack the blood cells, with disastrous and potentially deadly results for you.
The rarest blood type, Rhnull blood, is so called because it’s completely missing the most common type of antigen, Rh. This means that if you have it, receiving a transfusion of a blood type with any Rh antigens will cause your body to reject the blood.
Since 99.9999994 percent of people have blood with Rh antigens, finding a blood donor for Rhnull individuals can be nearly impossible. This is why people who have golden blood are encouraged to donate their blood in case they ever need blood, and because others with rare blood types could benefit from it.
Since Rhnull blood contains no Rh antigens to be rejected, it can be a universal donor for those with generally rare blood types.
Golden blood, therefore, can be both life-threatening and lifesaving. And while your chances of having the rarest blood type are incredibly low, finding out your blood type is the only way to know for sure.