A Genetic Bleeding Disorder
- The chromosome involved in this disorder is the x chromosome, a sex chromosome.
- The inheritance pattern shown in this disorder is x-linked because the genes involved can be found on the x chromosome.
- There are three different possibilities of what gene is affected as there are three different types of Hemophilia.
- Hemophilia A is the most common type. The gene affected here is the FVIII gene (the factor eight gene).
- The second most common type of hemophilia is hemophilia B, also known as the Christmas disease. FIX (factor nine gene) is the gene affected is this type of hemophilia.
- The third, final, and least common type of Hemophilia is Hemophilia C, which affects the factor six gene (FXI).
- There are several different types of mutations that can cause Hemophilia because there are three different types of the disease. The most common is a nonsense mutation.
*A nonsense mutation is when one of the bases in the codon that is supposed to present is changed to a different base a stop codon results. In the specific case of Hemophilia the codon CGA, which codes for the amino acid argenine, changes to the codon TGA, which is a stop codon.
* This mutation results in a protein that is a useless fragment and can not help with blood clotting.
- Blood begins to clot after an injury to a blood vessel occurs.
- The first step is to create a temporary plug with sticky blood cells called platelets.
- After that a more permanent structure is put up called fibrin. Fibrin is made of twenty different proteins called factors.
- The genes called factors that were mentioned earlier are the code to make these proteins.
- In hemophilia when a person cannot create one of the factors they can not make Fibrin fully. There will be 'holes' in the make up of the Fibrin which will not block the blood properly and it will continue to flow from the inured blood vessel.
- As with the genes there are three different proteins that can be affected each with the different types of Hemophilia. The genes and proteins share the same names.
- In hemophilia A the protein factor VIII is affected. This protein is simply called factor eight.
- The FIX gene codes for the protein factor IX called factor eight, and is affected in Hemophilia B.
- In the less common Hemophilia C the affected protein is factor XI (factor six), which gets coded for by the FXI gene.
- Because people who have hemophilia do not have enough of clotting factors they bleed excessively.
- Some cases of hemophilia are not nearly as severe as others. For example Hemophilia B and C are no where near as deadly and severe as Hemophilia A. In the same way some cases of Hemophilia A are much worse than other cases of Hemophilia A.
- In mild cases big problems with bleeding excessively may only occur when one gets surgery or dental procedures.
- Moderate cases of hemophilia are a little more problematic and may result in bleeding problems from a minor injury such as a fall.
- In very advanced cases of Hemophilia the person with the disorder may experience spontaneous bleeding caused by nothing at all, such as nose bleeds or bleeding from scratches that normal people wouldn't put any thought into.
- Some bleeding happens not just from cuts and scraps but also in soft tissues. Bleeding in these tissues can result in small lumps or bruises and usually go away on their own.
- Bleeding can also occur in muscles. This will be more painful and if the bleeding gets too bad they can cause damage to the nerves.
- Another more severe type of bleeding can occur in elbows and knees more commonly but also in all joints. Repeated bleeding in the same joints will eventually end up in deformed and permanently damaged joints.
- The most serious type of bleeding for Hemophiliacs is any bleeding in ones head. Bleeding in the head of any person may cause permanent damage, but for a hemophiliac it is likely to happen faster and less likely to be able to stop causing the person to die or have permanent brain damage.
- In some cases with all Hemophiliacs, if the accident they are apart of or they injury they sustain is too serious it will almost always result in death by bleeding out.
- There is no cure for hemophilia, but there are treatment options.
- Injections of missing clot factors can help hemophiliacs.
- Depending on what type of hemophilia they have determines what factor they get injected with.
- Time between treatments all depends on how severe the case of Hemophilia is. If it is not too severe than they may only need injections before major procedures, while people with severe cases may need regular injections.
- The problems with this type of treatment are diseases. The first caused by the people how donate their blood. The blood factors they donate will contain any disease they have, so if not tested properly a blood giver may pass on diseases such as HIV to the receiver of their blood.
- Another problem may occur when the person receiving the injections body begins to create antibodies to fight the injections because the body mistakes it for a disease.
- There has been testing for another kind of treatment for Hemophilia B patients in which they are injected with a virus called adeno-associated virus (AAV).
- This virus causes people who can produce blood factors normally to produce an over amount of the protein Factor IX.
- Because people who have Hemophilia B lack this protein it would probably allow them to produce a normal or closer to normal amount of the protein.
- In a test conducted patients actually did begin producing protein Factor IX after eight weeks and kept producing it for six months.
- With more tests and eventual approval Hemophiliacs may not need nearly as many treatments and may have to no longer live in fear.
Statistics and Additional Infomation
- In every 5,000 to 10,000 males only one worlds wide has hemophilia A.
- In every 20,000 to 34.000 males world wide only one has hemophilia B.
- There are about 5,000 Americans with hemophilia and about 80% of these 5,000 have type A of hemophilia.
- Family history plays a major role in who can get hemophilia; currently 80% of all hemophiliacs have a family history of the disorders. The other 20% have had the unfortunate occurrence of spontaneous gene mutation while their chromosomes were being split.
- Males are more common to get the disease than females as men have a more likely chance of inheriting the faulty genes because they only have one x chromosome.
- Hemophilia is known as the Royal Disease.
* The most well remember case is that of the son of Nicholas, a Czar of Russia, and his wife Alix. There son's name was Alexis (Alexei) and he had a very sever form of hemophilia.
*Rasputin was a man who was able to 'stop' the boys bleeding, so the Czar and his wife honored him. He was later thought to be responsible for the decline of Czarist Russia.
Alexis receiving a mud bath treatment for his hemophilia.
Alexis pictured with Rasputin who was supposed to be healing him.
Alix always blamed herself and felt guilty for the illness of her son Alexis.
Clark, Jim. "DNA Mutations: Hemophilia." UC Davis Chemwiki. Ed. Delmar Larsen. Delmar Larsen, 2009. Web. 31 Mar. 2016. <http://chemwiki.ucdavis.edu/Core/Biological_Chemistry/Nucleic_Acids/DNA/DNA%3A_Mutations>.
“Hemophilia.” Today's Science. Infobase Learning, Web. 24 Mar. 2016.
"Hemophilia." Sick! Detroit: UXL, 2007. Science in Context. Web. 24 Mar. 2016.
“Hope for Hemophiliacs.” Today's Science. Infobase Learning, Apr. 2000. Web. 24 Mar. 2016.
National Human Genome Research Institute, ed. "Learning About Hemophilia." National Human Genome Research Institute. USA Government, 27 Sept. 2011. Web. 29 Mar. 2016. <https://www.genome.gov/20019697>.
Picture 4: https://prezi.com/yrtm2wwcfzja/hemophilia/
Picture 11: https://www.pinterest.com/pin/88875792616438953/
Video Source: https://www.youtube.com/watch?v=oExbzAJP7t4