Carlos II of Spain, ‘The Bewitched’: cursed by aspartylglucosaminuria?

Carlos II of Spain (1661–1700), last of the Spanish Habsburgs, was known as The ‘Bewitched’ due to his multiple medical issues and feeble nature. He suffered from a range of ailments extending beyond the well-known Habsburg jaw, including developmental delay, intellectual disability, dysarthria, skeletal deformity, recurrent infections, epilepsy and infertility, among others. The Habsburg dynasty of Spain was characterised by marked inbreeding, and the male line died out with Carlos II. Various diagnoses have been proffered to explain Carlos II’s infirmity, though none have been full satisfactory to explain the full breadth of his ailments. As illustrated here, it may be that aspartylglucosaminuria, an autosomal recessively inherited lysosomal storage disorder, can account for both the characteristic facial features and the wide variety of other features exhibited by Carlos II.