The mutation in the hemophilia gene, which affects the clotting of blood, had likely arisen spontaneously in Queen Victoria at birth. Her eighth child, Leopold, had inherited the gene and died of a brain hemorrhage at age thirty. The gene had also been passed from Victoria to her second daughter, Alice—and then from Alice to her daughter, Alexandra, the czarina of Russia. In the summer of 1904, Alexandra—still an unsuspecting carrier of the gene—gave birth to Alexei, the czarevitch of Russia.
