Hilary Mantel, one my favorite authors (she wrote Wolf Hall and Bringing Up the Bodies, and won the Booker Prize), wrote a long but interesting article for the London Review of Books. She discusses everything from Marie Antoinette, Kate Middleton, Henry VII, and more.
As you may know, I like to read about Tudor England (Mantel’s books focus on the time). Henry VIII couldn’t produce a male heir, and this resulted in his many marriages as well as the birth of the Church of England (and “mainline Protestantism”?). Mantel writes about a paper describing a genetic deficiency which might have explained Henry’s difficulty:
Recently a new hypothesis about Henry has emerged. In 2010 a paper by Catrina Banks Whitley and Kyra Cornelius Kramer appeared in the Historical Journal, called ‘A New Explanation of the Reproductive Woes and Midlife Decline of Henry VIII’. It suggested that Henry had a blood type called Kells positive. People who are Kells positive carry an extra antibody on the surface of their red blood cells. The blood type is rare, so we can assume Henry’s wives were Kells negative, and that their lack of compatibility was the reason for the multiple reproductive failures. When a woman who is Kells negative conceives by a man who is Kells positive, she will, if the foetus itself is Kells positive, become sensitised; her immune system will try to reject the foetus. The first pregnancy will go well, other things being equal. As with rhesus incompatibility, it takes one pregnancy for the woman to develop the sensitisation. But later children will die before or just after birth.
I encourage you to read the entire article (lots of good stuff).
If you’re looking for something to read, both of her books are great!