Inbreeding Leds to the End of a Spanish Dynasty

 



Gonzalo Alvarez and colleagues at the University of Santiago de Compostela researched the Habsburg Dynasty of Spain and found significant inbreeding as reported by NBC News. The dynasty spanned 200 years and ended when King Charles II died and left no heirs to his throne. New evidence though shows that frequent inbreeding might have lead to the very ill and infertile conditions of Charles the second. Historical data shows that the Habsburg's wanted to keep their heritage on the thrown and would frequently inbred. During the 200 year span that they ruled there was eleven marriages, 9 of which had some type of inbreeding going on. The most significant were two uncle-niece marriages and one first cousin marriage. It is thought that this level of inbreeding is what cause all of the medical affects on King Charles II and the ending of the dynasty.
Alvarez and his team then took an inbreeding coefficient from Charles II and all his 3000 ancestors and found that the founder of the Dynasty Phillip I had a .025 coefficient while the last of the dynasty Charles II had a coefficient of .254! The .254 is almost as high of a coefficient of a direct parent-child or brother-sister relationship. Charles II was the offspring of a uncle-niece relationship and his grandfather was also the offspring of an uncle-niece relationship. This high coefficient directly relates to his small stature, weak body, intestinal problems, infertility, and sporadic hematuria or blood in urine. He also was unable to speak until age 4 and unable to walk until age 8, as well as being know to be "slow".
The average infant survival rate to the age of 1 was 60% and to the age of 10 was half. The spanish villager infant survival rate was around 80%, which is just staggering because the villagers had a higher success rate then royalty! All the inbreeding going on in the family, did get the Habsburg family what they wanted with "keeping it in the family", but without any knowledge of it being horrible for the offspring it lead to their demise.

http://blog.23andme.com/ancestry/the-end-of-a-dynasty-how-inbreeding-doomed-the-house-of-habsburg/