What Causes Hemophilia?

Hemophilia is a genetic disorder that affects the blood’s ability to clot properly. It is primarily caused by mutations in the genes responsible for the production of blood clotting factors. There are two main types of hemophilia, Hemophilia A and Hemophilia B, which differ in the specific clotting factor that is deficient. Hemophilia A is caused by a deficiency of clotting factor VIII, while Hemophilia B is caused by a deficiency of clotting factor IX.

Hemophilia is an X-linked recessive genetic disorder, which means it is carried on the X chromosome. Individuals typically have two sex chromosomes: females have two X chromosomes (XX), and males have one X and one Y chromosome (XY). Since the gene for clotting factors is located on the X chromosome, hemophilia is more commonly seen in males. Here’s how it is inherited:

  • Hemophilia in males: Males have one X chromosome and one Y chromosome. If they inherit a mutated X chromosome with the hemophilia gene from their mother, they will have hemophilia because they have only one X chromosome.
  • Hemophilia in females: Females have two X chromosomes. If they inherit one mutated X chromosome with the hemophilia gene and one normal X chromosome, they are considered carriers of the disorder. They may not exhibit severe symptoms but can pass the hemophilia gene to their offspring.
  • Hemophilia in offspring: If a carrier female with one mutated X chromosome has a child with a male who does not have hemophilia, there is a 50% chance that her sons will have hemophilia, and a 50% chance that her daughters will be carriers.

In some cases, hemophilia can also occur due to spontaneous genetic mutations, even if there is no family history of the disorder. These cases are less common but still occur.

Hemophilia affects the blood’s ability to clot properly, which can result in prolonged bleeding following injuries or surgeries. The severity of hemophilia can vary, with some individuals experiencing more severe symptoms and others having milder forms of the disorder. Hemophilia is a lifelong condition, and there is no cure, but it can be managed with appropriate medical care, including the administration of clotting factor replacement therapy to help prevent and treat bleeding episodes.