Understanding Hemophilia Genetics and Implications

Hemophilia is one of the first genetic disorders that have been discussed by ancient scholars. The affected gene can be due to inheritance or the result of a new mutation. In maximum cases however it is due to inheritance.

Hemophilia is an X-linked recessive trait. Hemophilia genetics means that for the disorder to surface in a child, both the X chromosomes of a girl child has to carry the trait. On the other hand for a boy child to have the hemophilia genetics, he must inherit the defective X chromosome from either parent, since men have only one X chromosome. Humans have 23 pairs of chromosomes. Out of which, one pair of chromosome is responsible for determining the sex of an individual, these are called sex chromosomes. While men have a combination of XY chromosomes, females are XX. Patients suffering from hemophilia have a faulty X- chromosome this hemophilia genetics can be inherited from either parents or can be the caused due a new mutation. Since women have two X-chromosomes, chances of them being haemophilic are greatly reduced since there is always an alternate X chromosome to counter the defective one.

Clotting factors are synthesized in the liver. A deficiency in the clotting factor means that the body does not manufacture it any more or manufactures it at extremely low levels which are not sufficient to promote clotting.

If the parents are haemophiliacs or carriers of the altered gene it is generally easier to trace the hemophilia genetics in the child as it would generally run down the family. Ascertaining hemophilia A in a child can be done as soon as he is born by taking samples of blood from the umbilical cord to check the count of the clotting factor VIII. However, tests for hemophilia B can only be done when the child is six months or older. Post six months, blood sample is checked for factor IX which determines whether the child is suffering from hemophilia B.

The nature of hemophilia genetics has been spoken about by ancient scientists and physicians like the renowned Albucasis of the 10th Century AD. In his writings he describes a family whose male members die of bleeding in spite of trivial injuries only. This means that he recognised the genetic nature of hemophilia and how it runs down a particular family.

The American physician Dr. John Conrad Otto in the 18th century also wrote down his observations with respect to hemophilia genetics. He observed the tendency of the disease to occur mostly in males and it being transmitted by females who remained unaffected by the disease. He recognised this as hereditary and studied a particular family whose male members suffered from hemophilia. He traced the history of the family to a woman who possible was the person from where the original mutation had occurred.

The primary part that hemophilia genetics play in the disorder has been traced and acknowledged over the years. The inherent nature of hemophilia led to the spread of the disease in many royal houses of Europe. Queen Victoria has been traced to be the carrier of the defected chromosome of hemophilia b which was later passed down to two of her daughters. These daughters, Alice and Beatrice were married into the royal houses of Spain and Russia. This led to widespread hemophilia b in the European royalty and led to the death of many heirs.

Since hemophilia is a genetic disorder, no therapy can cure it permanently. Temporary solutions like replacement therapy provide some relief to the hemophilia patients. Research is being made in the field of gene therapy which would permanently replace the defected gene with the corrected version.

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