Hemophilia By Trevor Nelson and Andy Lease

Types – Clotting Factors I Fibrinogen – Easy bruising II Prothrombin – Nosebleeds and bruising III Tissue Extract IV Calcium V - Joint bleeding and other symptoms VII – Mild effects VIII – Most common type (Hemophilia A) IX Christmas factor – The Christmas disease (Hemophilia B) X Plasma Thromboplastin Antecedent (PTA) – Joint bleeding XI Hageman factor – High occurrence in Jewish population XII – Little to no trouble clotting XIII Fibrin Stabilizing Factor – No trouble clotting, but after the clot is formed it is very weak

General Information Hemophilia is one of the oldest known genetic disorders. It is characterized by the inability for the blood to clot. It can lead to hemorrhages or excessive bleeding even from a minor scrape. Most hemophiliacs suffer from “arthropathy”, or bleeding in the joints. Bleeding occurs due to the inability for the body to produce the required clotting factors. 80% of all cases have an identifiable family history of the disease. The large majority of those affected by hemophilia are males. Approximately 1 in 10,000 males have hemophilia.

Background Hemophilia has been around for as long as human existence, but it became much more common since Queen Victoria and her descendants. So many people in her family had this disorder because they had a limited gene pool.

Royal Family Pedigree

Causes Hemophilia is primarily a genetic disorder, though about 20% of all cases have no genetic links. The 20% of cases not associated with genetic traits are due to a mutation in which a “jumping gene” disrupts the blood clotting ability of the clotting factor.

Causes Cont. In this punnett square the hemophilic gene is the h because it is the recessive trait. The H is healthy clotting and the o is irrelevant because it is on the Y chromosome. The genes of Hemophilia are on the X Chromosome. 25% are effected here. Key: Male Female XHXH YoYo XHXH XHXHXHXH XHYoXHYo XhXh XhXHXhXH XhYoXhYo

Cause Cont. When the mother is a carrier and the father is unaffected there is a 50/50 chance of their son having hemophilia and their daughter becoming a carrier. When the father is a carrier of hemophilia and the mother is not all the daughters will be carriers but their sons will be normal.

Cure In mild forms, plasma transfusions can be administered to help clot the blood. Physiotherapy can help to strengthen the muscles and joins, which will decrease the change for internal bleeding. Currently, research is being done that is attempting to alter the genetic makeup and change the clotting factor.

Source List Microsoft Encarta Encylopedia nfo.htmlHttp:// nfo.html tandards/curriculum/sci/g6sci/punnett.htmlhttp:// tandards/curriculum/sci/g6sci/punnett.html hema.htmlhttp:// hema.html