The rarest blood type
Japanese and other Asians put great store in knowing one’s blood type (“ketsuekigata”), the way that some Westerners know their zodiac signs and put store in their horoscopes. Knowing a person’s blood type is thought to reveal that person’s personality - at least, to an extent. Similarly, knowing the animal year of a person’s birth is thought to reveal the same. (For example, my wife, Junko, was born in the Year of the Dog. I was born in the Year of the Tiger. Dogs and Tigers are a good match, apparently. But I did not hear that until well after we were married.) One’s employment opportunities can be affected and in extreme cases even marriage engagements can be broken on the basis of an unfavorable blood type match. That’s how seriously it is still taken by some Japanese. For foreigners it is interesting at first. But soon the constant inquiries about our blood types - questions which we usually cannot answer because our blood type is meaningless to us - get a little tiring.
There is a blood type industry in popular Japanese culture that fuels the market for dozens of books on the topic seeking to analyze people, human behavior, social relationships and even historical and current world events from the perspective of the participants’ blood types. It is easy to dismiss it as poppycock until I remember the devotion of many Westerners to their daily horoscopes in newspapers and magazines.
Most humans blood types are either A, B, AB, or O. I used to say that my blood type was “Red”when Japanese asked me, just for a joke. But the truth is that I have a very rare blood type - Type X. Even English-speaking foreigners think I am joking when I say it, and it is true that most people are unaware of the rarest blood types - R, X and RX. Even some professional doctors are unaware. A haematologist (a blood and bone marrow specialist) will certainly know, but your local general practioner/family doctor may not.
The rarest blood type in the world is RX. There are only about 15,000 known living people with it. It features copper chemical bonds in the hemoglobin instead of the usual iron-based hemoglobin (that gives blood its red color). Next is Type R, with about twenty million people worldwide. Type R features an interesting and uncommon oxygen isotope. Finally, Type X, my blood type, is the third rarest represented by about eighty or ninety million people worldwide. X people’s blood is compatible as transfusion blood with Type As, Bs, and ABs, but our blood has a slightly different oxygen molecular structure - an extra atom on about 50% of the hemoglobin molecules. We are one of the many invisible minorities in the world walking the streets like a secret society or a fifth column, rubbing shoulders daily with all those unsuspecting A, B, AB and O types. Finally, this story is complete fiction.