Who is hemophilia inherited from

From Genetics Home Reference. Description Hemophilia is a bleeding disorder that slows the blood clotting process. Frequency The two major forms of hemophilia occur much more commonly in males than in females. Causes Changes in the F8 gene are responsible for hemophilia A, while mutations in the F9 gene cause hemophilia B. Learn more about the genes associated with Hemophilia F8 F9. Inheritance Hemophilia A and hemophilia B are inherited in an X-linked recessive pattern.

Research Studies from ClinicalTrials. Haemophilias A and B. Citation on PubMed Franchini M. Acquired hemophilia A. Citation on PubMed Giangrande P. Haemophilia B: Christmas disease. Expert Opin Pharmacother. Haemophilia A: from mutation analysis to new therapies.

Nat Rev Genet. Hemophilia A. Hemophilia B. New insight into the molecular basis of hemophilia A. Int J Hematol. Bleeding in carriers of hemophilia. The lower the amount of the factor, the more likely it is that bleeding will occur which can lead to serious health problems.

In rare cases, a person can develop hemophilia later in life. The majority of cases involve middle-aged or elderly people, or young women who have recently given birth or are in the later stages of pregnancy. This condition often resolves with appropriate treatment. Hemophilia is caused by a mutation or change, in one of the genes, that provides instructions for making the clotting factor proteins needed to form a blood clot.

This change or mutation can prevent the clotting protein from working properly or to be missing altogether. These genes are located on the X chromosome. Males inherit the X chromosome from their mothers and the Y chromosome from their fathers.

Females inherit one X chromosome from each parent. The X chromosome contains many genes that are not present on the Y chromosome. This means that males only have one copy of most of the genes on the X chromosome, whereas females have 2 copies. Thus, males can have a disease like hemophilia if they inherit an affected X chromosome that has a mutation in either the factor VIII or factor IX gene. Females can also have hemophilia, but this is much rarer.

In such cases both X chromosomes are affected or one is affected and the other is missing or inactive. In these females, bleeding symptoms may be similar to males with hemophilia. Sometimes a female who is a carrier can have symptoms of hemophilia. In addition, she can pass the affected X chromosome with the clotting factor gene mutation on to her children. Learn more about the inheritance pattern for hemophilia. Even though hemophilia runs in families, some families have no prior history of family members with hemophilia.

Blood contains many proteins, called clotting factors, that can help to stop bleeding after injury or surgery. People with hemophilia have low amounts of either factor VIII eight or factor IX nine , key factors responsible for normal blood clotting.

In people with hemophilia, there is a mutation difference from normal in either the gene for the factor VIII protein or the gene for the factor IX protein. Most people who have hemophilia are born with it. It almost always is inherited passed down from a parent to a child. There are no genes for clotting factors on the Y chromosome. Thus, if a male has a hemophilia allele on his only X chromosome, he will have the disorder.

A female with a hemophilia allele on one X chromosome usually has a normal allele on her other X chromosome that can produce normal clotting factor, so she has some protection against having hemophilia. A female with one hemophilia allele and one normal allele is called heterozygous or a carrier.