How do you get hymophilia?

Haemophilia is an inherited genetic disorder passed on from parents to children. It is caused by a deficiency or abnormality in specific clotting proteins in the blood, such as factor VIII or factor IX, leading to impaired blood clotting and increased bleeding tendency.

Haemophilia is primarily an X-linked recessive genetic disorder, meaning the affected gene is located on the X chromosome. Males are more commonly affected by haemophilia because they have one X and one Y chromosome, while females have two X chromosomes.

Here's how haemophilia is inherited:

1. Carrier Females: In the most common scenario, females can be carriers of haemophilia. This means they have one copy of the faulty gene on one of their X chromosomes, while the other X chromosome has a functional gene. Carrier females usually do not experience symptoms themselves but can pass the faulty gene to their children.

2. Affected Males: Males can inherit haemophilia when they receive the faulty gene from their carrier mother. Since males have only one X chromosome and one Y chromosome, if the X chromosome carries the faulty gene, they will have haemophilia.

3. Female Haemophilia: Rarely, females can also have haemophilia if they inherit the faulty gene from both their carrier mother and an affected father (who has haemophilia). This occurs when the father contributes an X chromosome with the abnormal gene, and the mother contributes her X chromosome with the same abnormality.

4. X-Linked Inheritance: The X-linked inheritance pattern of haemophilia determines how the condition is passed down through generations in a family. It is more prevalent in males, and carrier females can pass the faulty gene to their sons or daughters.

It's important to note that haemophilia A, caused by a deficiency of factor VIII, is more common than haemophilia B, which is caused by a deficiency of factor IX. Both types are inherited in the same manner, but the specific gene mutations responsible for each disorder are different.

Genetic counselling and testing can help individuals and families understand the risk of inheriting or passing on haemophilia and make informed decisions about family planning and medical care.