We saw this combination historically in European royalty, which was plagued by inbreeding. One particularly well-known instance: https://en.wikipedia.org/wiki/

We saw this combination historically in European royalty, which was plagued by inbreeding. One particularly well-known instance: https://en.wikipedia.org/wiki/Haemophilia_in_European_royalty https://en.wikipedia.org/wiki/Haemophilia_in_European_royalt... As for more modern times, surely the wealthy are especially cognizant of genetics, right? "Historically, populations of Qatar have engaged in consanguineous relationships of all kinds, leading to high risk of inheriting genetic diseases. As of 2014, around 5% of the Qatari population suffered from hereditary hearing loss; most were descendants of a consanguineous relationship." -- https://en.wikipedia.org/wiki/Inbreeding#Prevalence https://en.wikipedia.org/wiki/Inbreeding#Prevalence