King Henry VIII and the Kell Blood Group

Hans Holbein d. J. 074

King Henry VIII

(Hans Holbein the Younger [Public domain], via Wikimedia Commons)

A recent article on the DiscoveryNews website (King Henry VIII’s Madness Explained) suggests that King Henry VIII’s problems, and there were many of them, might be attributed to an X-linked disorder called McLeod syndrome and a rare blood type (Kell Positive) .

Since I am always on the lookout for new information to bring into the classroom, and I have grown tired of the usual hemophilia X-linked trait and the discussions of Rh factors, this article presented the chance to find out a little more about McLeod syndrome and Kell Positive. Plus, it always helps to have a colorful character to relate to, and the life of King Henry VIII certainly satisfied that criteria.

McLeod Syndrome

McLeod syndrome is rare X-linked genetic disorder (in a gene called XK; chromosome location Xp21.1) that produces a distorted form of red blood cell (RBC) called an  acanthocyte (star-shaped cell – see below).


By Rola Zamel, Razi Khan, Rebecca L Pollex and Robert A Hegele [CC-BY-2.0 (], via Wikimedia Commons

The XK gene is what is responsible for the synthesis of a protein that is active in a large number of cells, including those of the muscles, brain, and heart. The exact function of this protein is not yet known, but it appears to be involved in facilitated transport into or out of the cell.  In addition, on RBCs, the XK protein in  the formation of the Kell blood group – individuals who are Kell-positive have a defective XK gene lack the XK protein, and this appears to cause the odd-shape of the RBCs (although how is still a mystery). These cells can play havoc within normal circulation within the small boundaries of the capillary beds.

Back to Henry VIII

So what does this all have to do with Henry III? Historians have struggled for some time to determine what ailed Henry VIII. He suffered from a wide variety of disorders –  weakness in his muscles and skin ulcers, as well as depression, bouts of anger, etc. It is believed that he suffered a series of strokes before he died as well. Some experts believe that root disease was syphillis (after all – King Henry VIII was known for his active sex life), but another explanation may be Kell Positive syndrome. This blood group may also explain the frequent miscarriages by his wifes, since the Kell blood group can produce pregnancy complications similar to those found in the Rh blood group. For if Henry VIII was Kell-positive (only 9% of Caucasians possess this trait), and his wives were Kell-negative (which is probable), then he would pass the Kell-positive allele to the fetus (since this is an X-linked trait, and Henry VIII is a male), which potentially could cause an immune reaction against it by the woman’s tissues, resulting in a miscarriage. Since Kell-positive also produces the spiked RBCs, this could explain Henry VIII’s other symptoms.

Of course, we may never know if Henry VIII was Kell-positive, but it does provide an interesting way of discussing both blood groups and X-linked traits in the classroom.

Additional Information

%d bloggers like this: