The date of April 17 was chosen at the initiative of the World Federation of Hemophilia (WFH) and the World Health Organization (WHO) to draw attention to the problems of patients with blood clotting disorders.
What is hemophilia?
Hemophilia is a rare inherited blood disease that is characterized by increased bleeding due to impaired clotting process. Normal clotting prevents blood from hemorrhaging to muscles and joints (causing hemarthrosis and hematomas) and is also responsible for the cessation of bleeding in case of cuts and scratches.
The blood clotting process is quite complicated. It involves more than a dozen special proteins known as clotting factors. They comprise platelet (of which there are 22 kinds) and plasma proteins. The latter are denoted by Roman numerals from I to XIII. A deficiency of factor VIII is called hemophilia A and that of factor IX, hemophilia B.
Hemophilia inheritance diagram
Hemophilia A and B are unique in that, although the disorder is inherited along female lineage, its victims are almost exclusively men.
According to WHO statistics, about one in five thousand boys is born with hemophilia A. This is independent of ethnic or racial background. About one-third of hemophilia A patients have no familial history of such disorders.
It is now known to scientists that the disorder occurs in 30 to 40% of cases due to a spontaneous genetic mutation. Such patients would have no prehistory of cases among their relatives.
Genetic Heritage
Research of the disease began in 19th century. The term “hemophilia” was introduced by the Swiss doctor Friedrich Hopff in 1828.
Victoria, the Queen of England, was a known case – and other royal families inherited the disease from her. In Russia, hemophilia is often termed a “tsar illness,” because Alexey Romanov, the last heir to the throne of the Russian Empire, had been diagnosed with hemophilia.
Alexey Romanov
It is known that he suffered from poor blood clotting. However, this diagnosis was never supported by laboratory tests. Rather, it was based on increased bleeding, frequent hematomas and general sickness besetting the ill-fated boy.
Now that the possibilities of biochemical research are much greater, scientists from Russia and America have conducted an analysis of the DNA of the prince.
ЛLaboratory studies were performed by researchers at the University of Massachusetts Medical School, along with the head of the Laboratory of Molecular Brain Genetics of the Mental Health Science Center under Russian Academy of Medical Sciences, Doctor of Biological Sciences Yevgeny Rogayev.
In 80% of cases, the cause of hemophilia is a mutation of the F8 gene in the sexual X chromosome. However, such mutation was not discovered. An analysis of the DNA of the prince showed that such a mutation occurred in the neighboring F9 gene. This was proved for the remains of both Alexey and his sister Anastasia, and their mother, Alice-Alexandra. This is the kind of mutation that leads to the rather infrequent Type B hemophilia. Findings from the study indicate that the mutated F9 gene can be traced back to Queen Victoria. This is why men of subsequent generations suffered from hemophilia, and women only carried this recessive disease.
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