Archive for August, 2009


Rare Blood – Rh Negative and Otherwise

I’ve been researching various subjects for the sequel to my novel “In Our Image” and one of those subjects was “rare blood”.  Following in an excerpt from the sequel:

“I never knew there were minor blood groups,” Mary said.  “I thought if your blood type was A or B or O or AB, then that was it.   Of course the Rh positive/negative factor would also come in to play.”

“I never realized it either.  Once we got the results back from the amniocentesis test, we did some searching on the internet on the subject.   We found that there are over 200 minor blood groups, and these are considered rare.   All of these blood groups are minor to one of the four major groups, except for the Bombay blood group,” I responded.

“The Bombay blood group is extremely rare,” Alex added.  “It is estimated only a few thousand people in the entire world have it.   I think I read it occurs in only 1 out of 250,000 people.  At first they thought it was a minor group to the O major blood group, but upon further testing they found it was not.”

“How do these rare blood groups form?  What is their origin?” Anne asked.

“Ah, that is the question!  I don’t think anyone has a good answer to that one,” Alex responded.  “There are a lot of mysteries in life.  The origin of Rh negative blood is one of them.”

The fact that there are over 200 rare blood groups surprised me.  Each of these groups also have the Rh positive or negative factor associated with them.  From what I’ve read, the Bombay blood group is the rarest…do they also have the Rh+ and Rh- factors associated with this blood type?  If so, I wonder how many are Rh negative?

Following are links to interesting sites on rare blood: