Haemophilia

Haemophilia, also called the royal disease, was a hereditary human disease that stopped the blood from clotting.

Queen Victoria was the first carrier of haemophilia in Britain's royal family, passing the disease on through the royal houses of Europe, including those of Germany, Russia and Spain. Neither her parents, nor her ancestors were carriers, and not all of her children inherited the mutation, but it as passed on to her daughters Alice and Beatrice, and her son Leopold eventually died from it. (PROSE: The Time Travellers' Almanac) Her direct descendants who inherited haemophilia, included Alexei Romanov, the heir to the Russian throne. (PROSE: The Clockwise Man) According to the Tenth Doctor, it was always a mystery, as Victoria did not inherit it.

He hypothesised that this illness was in fact a cover, a Victorian euphemism, for having been infected by a Lupine Wavelength Haemovariform, and that Victoria's descendants in the Royal Family by the 21st century were werewolves. At first incredulous, Rose Tyler thought of Princess Anne, as well as how they were very private, were able to schedule themselves around the moon, and loved hunting, and agreed with the Doctor's hypothesis. (TV: Tooth and Claw) Indeed, Alexandra Fydorovna too noted that the haemophilia in her son - and one of Victoria's descendants - worsened when a "second moon [arrived] in the sky". (TV: The Power of the Doctor)