Catrina Banks Whitley and Kyra Kramer of Southern Methodist University have proposed a possible explanation for King Henry VIII of England’s reproductive problems. It all may have been due to an incompatibility of blood types.
Most people are familiar with ABO blood typing, which identifies one kind of antigen carried on a person’s red blood cells. If a person receives the wrong type of blood, his antibodies will attack the foreign antigens on those blood cells, leading to shock and even death. You may not know that there are 29 other blood-group systems, each of which involves a different set of antigens that can be targets for the body’s immune system.
One such system is the ‘Kell’ antigen system. If Kell positive man has a child with a Kell negative woman, her body will develop antibodies against that child in the womb. Usually, the first child of such a union is safe, but any subsequent Kell positive pregnancies will usually result in miscarriage, stillbirth or death soon after birth. Henry VIII’s six wives and various mistresses were known to have suffered at least eleven miscarriages. His first wife alone had at least six pregnancies, only one of which resulted in a surviving child. Atypically, that healthy child was not her first, but her fifth known pregnancy.
Besides the reproductive woes, Kell positive individuals sometimes suffer from McLeod syndrome, a condition that is similar to Huntington’s disease. Patients are typically fine for the first 30 or 40 years, and then begin to deteriorate both physically and mentally. This is consistent with Henry VIII’s transition from a sound young man to the paranoid immobile tyrant of his later years.
We’ll probably never know whether this explanation is correct. However, there is some evidence of the Kell positive phenotype in Henry VIII’s ancestry. The male descendents of his maternal great-grandmother Jacquetta of Luxembourg experienced a similar type of reproductive failure.