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Scientists in India successfully used gene therapy to treat five patients with severe Hemophilia A.
Over 14 months of follow-up, none of the patients experienced bleeding episodes.
Unlike regular treatment, which requires frequent injections of clotting factors, gene therapy introduces a gene that helps the body produce its own clotting factor, offering a potential one-time solution.
The trial, led by Alok Srivastava from the Christian Medical College, Vellore, was supported by the Indian government’s Department of Biotechnology.
A similar gene therapy, Roctavian, was approved in the U.S. in 2023, showing reduced bleeding episodes after treatment.
Hemophilia A
Hemophilia is a group of rare bleeding disorders caused by a congenital deficiency in specific clotting factors.
The most prevalent form is Hemophilia A.
Hemophilia A results from a deficiency in a crucial blood clotting protein known as factor VIII.
Due to this deficiency, individuals experience prolonged bleeding after injuries, as their blood takes longer to clot than usual.
Causes: It is primarily inherited (genetic) and follows an X-linked recessive pattern, meaning the gene responsible for factor VIII production is located on the X chromosome.
Males have one X and one Y chromosome, while females have two X chromosomes.
If a male inherits an X chromosome with the defective gene from his mother, he will have hemophilia A.
Females with one defective copy typically do not experience symptoms because the other X chromosome usually provides enough factor VIII.
However, females can have hemophilia A if they inherit two defective copies, one from each parent (much less common).
The severity of hemophilia A varies depending on the level of factor VIII activity in the blood.
Common symptoms can include:
Easy bruising and excessive bleeding from minor injuries (cuts, scrapes)
Bleeding in the joints (especially knees, elbows, and ankles), causing pain, swelling, and stiffness
Bleeding after surgery or dental procedures.
The treatment involves replacing the missing blood clotting factor so that the blood can clot properly.
This is typically done by injecting treatment products, called clotting factor concentrates, into a person’s vein.
The two main types of clotting factor concentrates available are:
Plasma-derived Factor Concentrates: Derived from human plasma, which is the liquid component of blood containing various proteins, including clotting factors.
Recombinant Factor Concentrates: Introduced in 1992, recombinant factor concentrates are genetically engineered using DNA technology and do not rely on human plasma.
They are free from plasma or albumin, eliminating the risk of transmitting bloodborne viruses.
However, gene therapy is now gaining prominence.
In recent trials, they used a new method that involves using a special type of virus called a lentiviral vector to insert a gene that produces FVIII into the patient's own stem cells.
These modified stem cells then produce FVIII when they develop into specific types of blood cells.
Acquired Hemophilia A:
While Hemophilia A is typically inherited, it can also be acquired later in life as a result of auto-antibodies targeting factor VIII.
This condition, known as acquired hemophilia A, is rare and differs from the congenital form in its onset and progression.
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