Hemophilia is a genetic disease that has plagued the royal houses of europe since the time of england's queen victoria, who was a carrier. her granddaughter alexandra married nicholas ii, the last tsar of imperial russia. alexandra was a carrier of the gene for hemophilia; nicholas was normal. their son, tsarevich alexis, was afflicted with the disease. alexis and his four sisters are all thought to have been killed at the outbreak of the revolution of 1917. it is likely that