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Mission Statement
About
Hemophilia
About
the DVC
About
the National Hemophilia Foundation
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About Hemophilia
More than 15,000 people in the United States have hemophilia
(either hemophilia A or hemophilia B). A person with hemophilia
has a missing or diminished amount of one of the factors
needed for normal blood clotting. Depending on the level
of these factors in the blood, hemophilia may be mild, moderate
or severe. About 60% of persons with hemophilia have severe
hemophilia A.They are at risk for bleeding after dental
work, surgery, and trauma. They also may suffer internal
bleeding with no trauma or injury and without apparent cause.
Repeated joint bleeds can lead to other health problems
and disabilities, including chronic joint problems and loss
of range of motion. About 15% of persons with hemophilia
have moderate hemophilia. These people are at risk for bleeding
after surgery or trauma, joint problems and rarely, spontaneous
bleeds. Twenty-five percent of people with hemophilia have
mild hemophilia. Their disease may be so mild that it may
go undetected until bleeding occurs after trauma or surgery.
The hemophilia gene is carried by females on one of their
X chromosomes and may be passed to their male offspring.
This is why hemophilia is called an X-linked genetic condition.
Female carriers of hemophilia have one X chromosome with
a working (normal) gene and one X chromosome with a nonworking
(defective) gene. There is a 50% chance the carrier will
pass the hemophilia gene on to male offspring. In other
words, there is a 50% chance that each of her male children
will have hemophilia. There also is a 50% chance the carrier
will pass the hemophilia gene on to her female offspring,
meaning that there is a 50% chance each of her daughters
will also be carriers.
In about a third of all cases there is no family history
of the disease, and hemophilia occurs as the result of a
new or spontaneous mutation. In such situations, the presence
of the hemophilia gene may only become apparent when the
mother is tested for carrier status after she gives birth
to a son with hemophilia.
Any male who inherits the defective X chromosome has hemophilia.
This is because males, unlike females, have only one X chromosome.
The Y chromosome is mainly involved in determining gender
and does not contain genes for the production of clotting
factors. Boys born to a father with hemophilia and a mother
who is not a carrier will not have the disease. This is
because boys get the X chromosome from their mother and
Y chromosome from their father. However, all daughters born
to men with hemophilia will inherit the father's hemophilia
gene. This is because they get one X chromosome from their
mother and one X chromosome from their father. They thus
will be carriers.
Some female carriers have no health problems or symptoms
related to carrying the hemophilia gene. These women are
known as asymptomatic carriers. However, other female carriers
have low factor levels that are associated with bleeding
problems. These symptomatic carriers may suffer excessive
menstrual bleeding, bruising, nosebleeds, and bleeding after
surgery, dental work, or childbirth. Stress, exercise, medicines,
and changing hormone levels during menstruation and during
and after pregnancy all may affect the bleeding patterns
of symptomatic carriers. Female carriers who have excessive
bleeding should be evaluated by a doctor skilled in treating
bleeding disorders. The Delaware Valley Chapter
can offer information about medical and other community
resources. return
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