Hemophilia is a rare inherited blood clotting disorder caused by deficient blood proteins. It is passed down from mother to son through genes on the X chromosome. Symptoms include prolonged bleeding from cuts or wounds and internal bleeding in joints that can lead to arthritis if untreated. Physicians test for hemophilia by ruling out other disorders and determining which clotting factor is deficient. About 1 in 4,000 males have the disorder. Treatment involves regularly injecting purified clotting factors to prevent or stop bleeding episodes.

1. HemophiliaBy: Allison Theuerl and Dylan Weidner

2. What Hemophilia is a rare inherited blood clotting disorder caused by inactive or deficient blood proteins.

3. How Hemophilia is inherited The genes for the clotting factors are located on the X chromosome. Therefore, hemophilia is a X linked disorder i.e, hemophilia is caused when a defective X chromosome gene is inherited. Females have two X chromosomes, one inherited from the father and the other from the mother; while a male has one X chromosome inherited from the mother and a Y chromosome inherited from the father. Consequently, a direct inheritance of hemophilia from the father to son is not possible. If a female inherits only one defective X chromosome, she does not suffer from the disorder. However, she will remain a lifelong carrier of the disease and may transfer the defective X chromosome to her male offspring. The probability of a female inheriting two defective X chromosomes is low and so this disease is seen predominantly in males. In this way, a criss-cross pattern of inheritance is observed in hemophilia. In such type of inheritance, there is no direct transfer of the affected genes from father to son or mother to daughter. Instead, the affected genes are transferred from the father to his daughter. The daughter is not affected by these genes but remains the carrier. She transfers the affected genes to her son. In all, hemophiliac genes are transferred from grandfather to grandson through the daughter.

4. The symptoms of HemophiliaPeople with Hemophilia bleed longer because their blood doesn’t clot well. Without treatment, a person with severe Hemophilia can bleed to death. With treatment, internal bleeding in the joints is the most problematic complication, because it leads to painful arthritis.

5. How Hemophilia is testedA physician will use several blood texts to rule out the other blood disorders before diagnosing Hemophilia. The final test determines which factor is responsible and the factors activity level. Genetic testing can uncover carriers and people with mild Hemophilia.

6. Occurrence of HemophiliaHemophilia is a sex-linked disorder that affects males of all races and ethnic groups. About 1 in 4,000 males are born with the disorder. Females can have the disorder but it is significantly rare.

7. Treatment for HemophiliaPeople with Hemophilia inject themselves with purified clotting factors to prevent or stop bleeding episodes. Additional treatment is necessary if the person’s immune system attacks the injected clotting factors.

8. Other information about HemophiliaIn the early 1980’s, most people with Hemophilia were infected with HIV, because the factors used for treatment were isolated from infected human plasma. Since then, virus-sterilizing techniques and the use of artificial factors have greatly reduced the risk.

9. Person affected with Hemophiliahttp://www.ygyh.org/hemo/have01.htm

10. Work Citedhttp://www.ygyh.org/hemo/whatisit.htmhttp://www.webmd.com/http://www.ncbi.nlm.nih.gov/disease