Hemophilia: "The Royal Disease" by Yelena Aronova-Tiuntseva and Clyde Freeman Herreid
University at Buffalo, State University of New York
Hemophilia is an X-linked recessive disorder characterized by the inability to properly form blood clots. Until recently, hemophilia was untreatable, and only a few hemophiliacs survived to reproductive age because any small cut or internal hemorrhaging after even a minor bruise were fatal. Now hemophilia is treated with blood transfusions and infusions of a blood derived substance known as anti-hemophilic factor. However, such treatment is very expensive and involves the risk of contracting AIDS. Hemophilia affects males much more frequently (1 in 10,000) than females (1 in 100,000,000). This occurs because a critical blood clotting gene is carried on the X chromosome. Since males only carry one X chromosome, if that is defective, hemoph ilia will immediately show up. An early death is likely. Females, on the other hand, carry two X chromosomes. If only one is defective, the other normal X chromosome can compensate. The woman will have normal blood clotting; she will simply be a carri er of the recessive defective gene. This fact will be discovered if some of her children are hemophiliacs. Naturally, women hemophiliacs are rare because it takes two defective X chromosomes in order for the condition to be seen. Hemophilia has played an important role in Europe's history, for it suddenly cropped up in the children of Great Britain's Queen Victoria. It became known as the "Royal disease" because it spread to the royal families of Europe through Victoria's descendants. Queen Victoria had always been worried about the quality of the blood of the British royal family. Her feelings about the necessity of revitalizing what she called the "lymphatic" blood of their houses are reflected in her letter to her daughter Vicky: "I do wish one could find some more black eyed Princes and Princesses for our children! I can't help thinking what dear Papa said that it was in fact when there was some little imperfection in the pure Royal descent that some fresh blood was infused... For that constant fair hair and blue eyes makes the blood so lymphatic... it is not as trivial as you may think, for darling Papa often with vehemence said: "We must have some strong blood."