Henry VIII, McLeod syndrome and Jacquetta's curse.

The mental decline of King Henry VIII from being a jovial, charismatic and athletic young man into an increasingly paranoid, brutal tyrant in later life, ever more concerned at his lack of one or more male heirs, has attracted many medical diagnostic theories. Previous hypotheses have included diabetes, syphilis and hypothyroidism, among others. However, these inadequately explain Henry's failure to produce a male heir, despite multiple pairings. The latest postulated diagnoses for Henry are the coexistence of both Kell blood group antigenicity (possibly inherited from Jacquetta Woodville, Henry's maternal great grandmother) causing related impaired fertility, and McLeod syndrome, causing psychotic changes. As the mutated McLeod protein of the syndrome significantly reduces the expression, effectively inactivating the Kell antigen, we critically review this theory, examining in detail the pathophysiology of these conditions and assessing the genealogy of Henry VIII and its effect in subsequent generations.