This post is for the lovely lady who admins the Tudor Fan Page on Facebook, who wanted to give her readers a quick & dirty summation of the theory that Henry VIII’s blood was positive for the Kell antigen and that he subsequently developed McLeod syndrome.
Most people don’t know it, but red blood cells have other antigens than just the ABO that determine your blood type. One of these antigens, the Kell antigen, can cause problems in pregnancy if fetus is Kell positive and the mother is not. The mother’s body attacks the fetus as “foreign” tissue and the baby is either miscarried later in the pregnancy, born dead, or born prematurely and then died of hemolytic disease of the newborn (HDN). Until 1963 nothing could be done to save the baby. The first baby is usually okay because the mother’s antibodies doesn’t typically kick in until the second pregnancy.
To have a Kell positive fetus in an Kell negative woman requires that the father be a Kell positive man who gave the fetus a Kell positive gene. Less than 10% of men have the Kell antigen in England, so it’s not a common problem but it isn’t rare, either. If Henry had Kell positive blood, it would explain why his wives kept loosing babies late in the pregnancy or shortly after birth. Any baby that didn’t get the Kell antigen gene from Henry would be healthy, which is why his daughter Mary survived despite being the fifth child born. All the rest of Henry’s surviving children (proven or in theory) were the first and/or only pregnancy of his partner. Any woman with whom he definitely had more than one pregnancy (Catharina of Aragon and Anne Boleyn) had multiple reproductive tragedies.
If the king had Kell positive blood, then he might have developed the rare condition known as McLeod syndrome. Onset of this disease is always around the 40th birthday, and gets worse over time. There are many, MANY symptoms of McLeod syndrome and patients tend to have them to varying degrees. Sometimes the symptoms involve a personality change so severe it is misdiagnosed as schizophrenia. Up until 1531, Henry’s 40th birthday, the king was still trying to use diplomacy to sort out his tangled love life. He grew increasingly fractious after that and in 1535 he started to slaughter people who opposed him. By 1536 he was so paranoid he thought Anne Boleyn had slept with more than 100 men and he had her beheaded for treason. It was nothing but downhill from there. When he died in 1547 he was a monster who had killed most of his relatives and friends. Sadly, his first 40 years of genial rule are forgotten and only the despotism of his later life is remembered.
If you want to read a slightly more detailed summery of the theory, you can find it in an article on Science Daily.
If you want all the details plus the context and medical history, you can buy my book Blood Will Tell: A Medical Explanation for the Tyranny of Henry VIII in either paperback or for an e-reader.
Happy reading, Tudor Fan Page!