Hemophilia related F8 and F9 genes are located on X chromosome.
Hemophilia is a rare genetic disorder which causes blood to clot abnormally. It is caused by deficient blood clotting factors.

Genetic variants that occur in the F8 (Factor VIII) or F9 (Factor IX) gene disturb the normal production of blood clotting factors.

Two Types

  • If the gene variant resides within the F8 gene, it is classified as Hemophilia A
  • If the gene variant resides within the F9 gene, it is classified as Hemophilia B


Map background and words saying "It is estimated that there are more than 400,000 cases of hemophilia worldwide."


It is estimated that ~400,000 cases of hemophilia exist worldwide.


The time of onset and detection of the symptoms depends on the severity of hemophilia.

According to the CDC, if the symptoms are relatively mild, the diagnosis takes about 36 months, while diagnoses of children with severe hemophilia take 1 month.


Six symptoms of Hemophilia: Unexplained and excessive bleeding from injuries, Easily bruised skin, Unusual bleeding after vaccinations, Pain, swelling or tightness in the joints, Blood in the urine or stool, Frequent and hard-to-stop nosebleeds

Inheritance Pattern

Two family trees showing the X-linked inheritance pattern of hemophilia in each case of parents affected.
Hemophilia is inherited in an X-linked recessive pattern.

There are more female carriers than male carriers, as the chances for women to have two affected X chromosomes are rare.

However, 10% of carrier females can be at risk y having less than half the normal amount of blood clotting factors.


Screening tests and clotting factor tests are commonly used in diagnosing hemophilia.

About two-thirds of newborn babies with hemophilia have a family history. In this case, a clotting factor test is usually conducted to check the level of Factor IIIV and Factor IX.

Since Factor IX is developed later, the level of Factor IIIV is more important.

The other one-third of newborn babies with hemophilia do not have a family history. In this case, the detection of hemophilia depends on the seriousness of the symptoms.

Genetic testing can be used to confirm the diagnosis and better estimate the risk of inhibitor formation.


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  2. Clotting Factor Replacement
    Acting as the primary treatment for hemophilia, clotting factor replacement is enacted by injecting the specific type of clotting factor which is deficient. By doing this, bleeding episodes can be prevented or treated in a more manageable manner.

    Desmopressin is a man-made form of vasopressin. For some types of mild hemophilia, the hormone can stimulate our body to release more blood clotting factors.

    Gene Therapy
    Many companies are developing gene therapies which allow patients to generate their own clotting factors via a single treatment. If the treatment is approved and be available for use, hemophilia is expected to be cured.

Living with HEMOPHILIA

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  2. Maintain a Healthy Diet
    Obesity is an ongoing issue in the hemophilia community. Maintain a healthy diet so that the joints are not exposed to excessive strain.

    Be Physically Active
    Avoiding physical activities may prevent the chances of bleeding episodes. However, recent studies have found that appropriate physical activities can improve balance and coordination, fight depression, and help reduce pain. Talk to your healthcare provider to discuss which activities suit you.

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