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| Philip I of Castile (1478-1506) |
Welcome to the second instalment in my series on royal families and the genetic disabilities that they passed down. If you found last week’s post on Tutankhamun interesting, then you are in for a real treat.
This week I will be examining the Spanish Habsburg dynasty, and particularly their last king, Charles II (1661-1700).
Before I begin, I must confess that this topic involves several numbers, as well as scientific studies, much of which went straight over my head.
Who were the Habsburgs with their jaw dropping looks?
The House of Habsburg was one of the most powerful royal families to exist in European History. They date back to the 11th Century and ruled the Duchy of Austria up until 1918, when they apparently lost a war. It was not just a long period they ruled over, but also a vast territory. Throughout the centuries, they ruled (deep breath): Austria, Germany, The Holy Roman Empire, Bohemia, Hungary, Croatia, Spain, Portugal, as well as overseas territories such as Mexico. That is a lot of ground to cover, literally. Is it possible to cover several centuries of history, over more than one continent in the space of a few paragraphs? Not a chance! I would have to live for hundreds of years to attempt that feat.
Instead, I will look at a very specific aspect of one branch of the family. In 1496, Philip I, son of the Holy Roman Emperor, married Joanna of Castile and Aragon, which would later become Spain. Thus, the reign of the Spanish Habsburgs had begun! They would rule successfully for 200 years, until the death of the childless Charles II killed off the bloodline in 1700. I will be coming back to that later. Many of the Spanish Habsburgs shared the same facial characteristic known as the ‘Habsburg Jaw’. This consisted of a large protruding jaw, also known as mandibular prognathism. They also had overhanging noses and enlarged lips which are characteristics of maxillary deficiency. The combination of these deformities made it difficult for some Habsburg kings to even close their mouths.
Was the Habsburg Jaw a result of Inbreeding?
Researchers decided to investigate whether the Habsburg Jaw was a result of inbreeding or some other cause. That reminds me, I forgot to mention, that as the Habsburgs gained the Spanish throne through marriage, they were afraid that they would also lose it through marriage. I can picture the scene now, the Habsburg ruler sitting in his court, when suddenly a candle (they didn’t have lightbulbs) flickers above his head. He proudly declares to his courtiers, “To preserve our hold on our kingdoms, cousins shall marry cousins, and uncles shall marry nieces!!” In my head he then lets out an ominous laugh.
Anyway, the researchers were able to analyse how closely related various members of the Spanish Habsburgs were, using something they called the inbreeding coefficient. They examined 16 generations of the family and more than 3,000 individuals. The results showed that Philip I (1478-1506), also known as Philip the Handsome, had a score of 0.025. However, Charles II (1661-1700), who was anything but handsome, had a score of 0.254. To put that into context, the offspring of first cousins would have an inbreeding coefficient of 0.0625. Charles II’s score indicates that his parents were either brother and sister, or parent and child. However, this was not the case. His father, Philip IV of Spain, was the uncle of his mother, Mariana of Austria. The high inbreeding coefficient was a result of such relationships happening for 16 generations! Harmful genes therefore increased as time went by as there were no new genes to overcome them. The researchers ultimately found that the people with the most severe Habsburg Jaw, also had the highest inbreeding coefficient.
It is important to note that while inbreeding is taboo in Western culture, it is still a common practice in certain parts of the world.
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| Charles II of Spain (1661-1700) |
Charles II
So, the Spanish Habsburgs were inbred, why is that in a blog post about disability history? Charles II, that’s why! Charles II of Spain lived with an array of physical and mental disabilities, dying childless at the premature age of 39. His nickname was El Hechizado (“The Hexed”), as many people, including Charles, believed that he was the subject of a curse. His jaw was so bad that it was said that his two sets of teeth did not meet and therefore, he could not chew, forcing him to swallow food whole. This wreaked havoc on his digestive system, and he had frequent bouts of vomiting and diarrhoea. He was described as having very little interest in his surroundings and was practically senile by the time he died. As indicated before, he was believed to be infertile, having no children from two marriages. He was also slow at developing, as he did not speak until the age of 4, and he could not walk until he was 8. It is now believed that two genetic disorders, combined pituitary hormone deficiency (CPHD, OMIM 26260) and distal renal tubular acidosis (dRTA, OMIM 602722), can explain most of his ailments. Other researchers suggest that he may have also lived with hydrocephalus as upon death, the coroner stated that his head was full of water. Whatever the case may be, it is clear that the history of inbreeding in his family severely impacted his life.
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Next week I will begin to examine the history of disabled people being used for entertainment purposes, starting with Ancient Rome.
The Wheelchair Historian
Further Reading
Alvarez G, Ceballos FC, Quinteiro C (2009) The Role of Inbreeding in the Extinction of a European Royal Dynasty. PLoS ONE 4(4): e5174. https://doi.org/10.1371/journal.pone.0005174 Accessed: 25 September 2020.
Álvarez, G, Ceballos, FC, and ‘Royal dynasties as human inbreeding laboratories: the Habsburgs’ Heredity (2013) 111,114–121&2013 Macmillan Publishers Limited All rights reserved 0018-067X/13www.nature.com/hdy Accessed: 25 September 2020.
‘The Habsburg Jaw And The Cost Of Royal Inbreeding’ Published June 20, 2018, Updated June 24, 2020 https://allthatsinteresting.com/habsburg-jaw Accessed: 25 September 2020.
Gregory, Andy, ‘Centuries of inbreeding to blame for ‘Habsburg jaw’ among European royals, study finds’, Monday 02 December 2019 12:31 https://www.independent.co.uk/news/science/habsburg-jaw-royal-family-inbreeding-facial-deformity-spain-austria-holy-roman-empire-a9229071.html Accessed: 25 September 2020.
Holloway, James, ‘Royal portraits confirm "Habsburg jaw" was caused by inbreeding’, December 02, 2019 https://newatlas.com/science/habsburg-jaw-inbreeding/ Accessed: 25 September 2020.
Saplakoglu, Yasemin, ‘Inbreeding Caused the Distinctive 'Habsburg Jaw' of 17th Century Royals That Ruled Europe’, December 02, 2019 https://www.livescience.com/habsburg-jaw-inbreeding.html Accessed: 25 September 2020.
Thompson, Andrea, ‘Inbreeding: Downfall of a Dynasty’, April 14, 2009 https://www.livescience.com/3504-inbreeding-downfall-dynasty.html Accessed: 25 September 2020.
Thulin, Lila, ‘The Distinctive ‘Habsburg Jaw’ Was Likely the Result of the Royal Family’s Inbreeding’, smithsonianmag.com, December 4, 2019, https://www.smithsonianmag.com/smart-news/distinctive-habsburg-jaw-was-likely-result-royal-familys-inbreeding-180973688/ Accessed: 25 September 2020.
Turliuc M, D, Cucu A, I, Perciaccante A, Tosolini G, De Luca S, Costachescu B, Costea C, F: ‘Hydrocephalus of King Charles II of Spain, the Bewitched King’. Eur Neurol 2019;81:76-78. doi: 10.1159/000500719 Accessed: 25 September 2020.
Yong, Ed, ‘How inbreeding killed off a line of kings’, April 14, 2009 https://www.nationalgeographic.com/science/phenomena/2009/04/14/how-inbreeding-killed-off-a-line-of-kings/ Accessed: 25 September 2020.
