A bump, a cut, a spontaneous bleed? Life-threatening? Surely not but if you carry the mutated gene for blood clotting, those events could be. The blood clots through a series of chemical reactions that require proteins at each step. If one of these clotting factors is in low supply or missing, the bleed continues. It could be through an open wound or it could be internal into a joint or organ. When the pressure builds up tissues are damaged and if the bleed continues may prove fatal. Until recently, the treatment has been to periodically replace the clotting factors through transfusions of the missing clotting factor.
Manufacture of the clotting factors is under genetic control and hemophilia is most likely to affect males because the mutation is carried on the X-chromosome. It is recessive and since females would need two copies of the defective gene, few of them are affected. They can be carriers, however, and pass the disease to sons through the X chromosome.
There are two main types of hemophilia, A and B. A is more common and B, known as Christmas disease, affects fewer people. It is hemophilia B that has been treated with gene therapy. In this form, clotting factor IX is in low concentration and the gene for its manufacture doesn't work properly. Researchers in Philadelphia cooperating with Canadian doctors have infused a harmless virus with a "good" copy of the defective gene into the livers of 9 patients. The results have been more than encouraging. At this point, some of the subjects have been free of symptoms (any bleeds) for up to a year. The introduced gene is busy making factor IX and their blood is clotting.
This could be a cure, freeing victims of hemophila from treatments that increase their exposure to blood-borne infections like HIV and hepatitis. Patients can take part in everyday activities without the fear that an inadvertent bump will set of an internal bleed. Spontaneous bleeds won't occur.
The woman in the picture is Queen Victoria. It is believed that a spontaneous mutation in her DNA introduced hemophilia to the European Royal Families. She had nine children, of whom two females were carriers and one male was hemophiliac. In 2009, genetic research was able to identify the disease as Hemophilia B.
Hemophilia B hasn't been cured. The gene therapy needs to last for the patient's lifetime. There are other unknowns and the study included only 9 subjects. It does provide hope for the thousands of hemophiliacs who have had to lead sheltered lives. Even bumping a knee could lead to a serious bleed into the joint. Researchers are hopeful and patients wish that the treatment is a success and works for all with hemophilia B.
This shows a knee joint of a hemophiliac who is experiencing a bleed.
I've been writing on and off for years and this is where my more serious pieces will be.