What is hemophilia?
Hemophilia is a rare hereditary bleeding disorder when
blood can't clot normally when that person is wounded or injured. It happens
because certain blood clotting factors are missing or do not work like they should. This
can cause excessive bleeding from a cut or wound. Random internal bleeding
can occur as well, especially in the joints and muscles. Hemophilia occurs more in males
than in females.
There are two types of inherited hemophilia:
Type A, the most common type, is caused by a deficiency of
factor VIII, one of the proteins that helps blood to form clots.
- Type B hemophilia is caused by a deficiency of factor IX.
Hemophilia is usually diagnosed at birth but the disorder can also be
acquired later in life if the body begins to make antibodies that attack and can
destroy clotting factors. Although, the noninherited or acquired type of
hemophilia is very rare.
Hemophilia is usually diagnosed at birth but the disorder can also be
acquired later in life if the body begins to make antibodies that attack and can
destroy clotting factors. Although, the noninherited or acquired type of
hemophilia is very rare.
How hemophilia is inherited?
Hemophilia type A and type B are inherited in an X-linked recessive
pattern. The x chromosome contains the genes that are involved with this disease, which is one of the two sex chromosomes. In males, one changed copy of the gene in each cell is enough to cause the condition. Although In females both copies of the gene would have to be mutated in order to cause the disorder. Because it is not very common that females will have two changed copies of this gene. therefor males have more of a chance to get the disorder than females. Also fathers cannot pass x-linked traits to their son.
punnet square
This is a punnet square showing a cross between a male with hemophilia and a woman without hemophilia and the possible outcomes.
Genotypes:
Aa:aa
2:2
phenotype:
has hemophilia: doesnt have hemophilia
2:2
Genotypes:
Aa:aa
2:2
phenotype:
has hemophilia: doesnt have hemophilia
2:2
Pedigree
In this pedigree it shows how hemophilia can posibly be passed down between three generations. The squares represent male and the circles represent females. If a square is filled all the way in then that individual has the disorder but if it is only half way filled in then that person is a carrier.
Symptoms.
The symptoms vary depending on what type of hemophilia the person
has but one of the main symptoms of hemophilia is extended bleeding.
Mild cases may go unnoticed until later in life, when they occur during
surgery or after trauma. Bleeding may occur without any cause. Internal
bleeding may also occur anywhere as well as bleeding into the joints.
Treatment.
Normal treatment takes replacing the missing clotting factor through a
vein. Diagnosing a bleeding disorder is important so that the doctor can take extra
care if you need surgery, and can test or warn other family members who might be
affected.
vein. Diagnosing a bleeding disorder is important so that the doctor can take extra
care if you need surgery, and can test or warn other family members who might be
affected.
Recommendations.
If your family has had a line of hemophilia you might want to consider going to a genetic counseler to see if you or your children have a risk of getting this diease.
Sources.
Information from:
http://my.clevelandclinic.org/disorders/hemophilia/hic_what_is_hemophilia.aspx
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001564/
http://ghr.nlm.nih.gov/condition/hemophilia
http://www.mayoclinic.com/health/hemophilia/DS00218
Pictures from:
http://www.hemophiliavillage.com/hemophilia-overview/what-is-hemophilia.aspx
http://my.clevelandclinic.org/disorders/hemophilia/hic_what_is_hemophilia.aspx
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001564/
http://ghr.nlm.nih.gov/condition/hemophilia
http://www.mayoclinic.com/health/hemophilia/DS00218
Pictures from:
http://www.hemophiliavillage.com/hemophilia-overview/what-is-hemophilia.aspx