Hemophilia

Hemophilia is a bleeding disorder that slows the blood clotting process. People with this disorder experience prolonged bleeding following an injury, surgery, or having a tooth pulled. In severe cases, heavy bleeding occurs after minor trauma or in the absence of injury. Serious complications can result from bleeding into the joints, muscles, brain, or other internal organs. The major types of this disorder are Hemophilia A and Hemophilia B. Although the two types have very similar signs and symptoms, they are caused by genetic changes in different genes. People with an unusual form of Hemophilia B, known as Hemophilia B Leyden, experience episodes of excessive bleeding in childhood, but have few bleeding problems after puberty. Another form of the disorder, acquired Hemophilia, is not caused by inherited genetic changes.

Genetic Mutations: Hemophilia is caused by genetic mutations, also known as pathogenic variants. Genetic mutations can be hereditary, when parents pass them down to their children, or they may occur randomly when cells are dividing. Genetic mutations may also result from contracted viruses, environmental factors, such as UV radiation from sunlight exposure, or a combination of any of these.

If you suspect you may have this disease, you may want to start collecting your family health history. Information such as other family members who have had similar symptoms, when their/your symptoms first appeared, or exposures to any potential disease-causing environmental factors should be discussed with your medical team. 

Yes. It is possible for a biological parent to pass down genetic mutations that cause or increase the chances of getting this disease to their child. This is known as inheritance. Knowing whether other family members have previously had this disease, also known as family health history, can be very important information for your medical team. This tool from the Surgeon General can help you collect your family health history.

There are multiple ways, or patterns, a disease can be inherited depending on the gene(s) involved. Based on GARD’s current data, this disease can be inherited in the following pattern(s):

X-Linked: X-linked inheritance means the genetic mutation is located on the X chromosome, one of the sex chromosomes. The male sex chromosome pair consists of one X and one Y chromosome (XY). The female sex chromosome pair consists of two X chromosomes (XX). Because males have just one X chromosome, it takes only one copy of the mutated gene to cause the disease. Females that have one copy of the mutated gene may have symptoms similar to those experienced by affected males, but usually have less severe symptoms, or no symptoms at all.

Female parents with one X-linked mutated gene have a 50% chance of passing on the mutation to each of their biological children. Male parents with an X-linked mutated gene will pass on the mutation to all their female children but cannot pass the mutation on to their male children.