Examining The Blood Disorder Of Haemophilia Biology Essay

Haemophilia, or hemophilia is a group of inherited blood disorders in which the blood does not clot properly. Known as a rare disease to individuals, Haemophilia has two main inheritable types, Haemophilia and Haemophilia B. Haemophilia is due in part to defective blood vessels, coagulation mechanisms or blood platelets. An affected individual may bleed spontaneously or for longer than a healthy person after injury or surgery. The paper will discuss in detail and in parts what exactly these diseases are, who suffers from them, what causes them, characteristic traits, statistics, locations , what are symptoms and treatments , research on the subject as well the social impact of these diseases. Many of those who suffer from these diseases have many changes and things they must do so they will not die from the complications of their diseases. The paper uses much information from many distinguished sources and cites them at the end of the paper. The paper also uses diagrams to help show how the genetics of passing down the defective genes.

What is Haemophilia ?

Hemophilia is a group of inherited blood disorders in which the blood does not clot properly. Known as a rare disease Bleeding disorders are due in part to defectsive blood vessels, coagulation mechanisms or blood platelets. An affected individual may bleed spontaneously or for longer than a healthy person after injury or surgery. The blood coagulation mechanism is a process which transforms the blood from a liquid into a solid, and involves several different clotting factors. The mechanism generates fibrin when it is activated, which together with the platelet plug, stops the bleeding. When coagulation factors are missing or deficient the blood does not clot properly and bleeding continues. Hemophilia can be divided into two major types: hemophilia A or hemophilia B. 9 out of 10 people who have hemophilia will have type A hemophilia which means the body is missing or has low levels of clotting factor 8. If the person has type B, then they are missing or have low levels of clotting factor 9.

In addition, hemophilia is usually genetically acquired but some can develop hemophilia during their lifetime. This can happen if the body forms to the clotting factors in your bloodstream. The antibodies can prevent the clotting factors from working.

What causes haemophilia ?

Haemophilia is caused by a malfunction in the X chromosome. To most recessive sex-linked, X chromosome disorders, haemophilia is more likely to occur in males rather than females. This is because females have two X chromosomes while males have only one, lacking a ‘back up’ copy for the defective gene; meaning, the defective gene is guaranteed to manifest in any male who carries it. Because females have two X chromosomes and because haemophilia is rare, the chance of a female having two defective copies of the gene is very low, thus females are almost exclusively asymptomatic carriers of the disorder. Female carriers may inherit the defective gene from either their mother, father, or it may be a new mutation. Only under rare circumstances do females actually have haemophilia.

(Center for Disease Control)

Who suffers from Haemophilia

Females possess two X-chromosomes, males have one X and one Y chromosome. Since the mutations causing the disease are recessive, a woman carrying the defect on one of her X-chromosomes may not be affected by it, as the equivalent allele on her other chromosome should express itself to produce the necessary clotting factors. However, the Y-chromosome in men has no gene for factors VIII or IX. If the genes responsible for production of factor VIII or factor IX present on a male’s X-chromosome are deficient there is no equivalent on the Y-chromosome, so the deficient gene is not masked by the dominant allele and he will develop the illness.

Since a male receives his single X-chromosome from his mother, the son of a healthy female silently carrying the deficient gene will have a 50% chance of inheriting that gene from her and with it the disease; and if his mother is affected with haemophilia, he will have a 100% chance of being a haemophiliac. While, for a female to inherit the disease, she must receive two deficient X-chromosomes, one from her mother and the other from her father (who must therefore be a haemophiliac himself). Hence haemophilia is far more common among males than females. However, it is possible for female carriers to become mild haemophiliacs due to inactivation of the X chromosomes. Haemophiliac daughters are more common than they once were, as improved treatments for the disease have allowed more haemophiliac males to survive to adulthood and become parents. Adult females may experience heavy periods due to the bleeding tendency. The pattern of inheritance is criss-cross type. This type of pattern is also seen in colour blindness.

A mother who is a carrier has a 50% chance of passing the faulty X chromosome to her daughter, while an affected father will always pass on the affected gene to his daughters. A son cannot inherit the defective gene from his father.

As with all genetic disorders, it is of course also possible for a human to acquire it spontaneously through mutation, rather than inheriting it, because of a new mutation in one of their parents’ gametes. Spontaneous mutations account for about 33% of all cases of haemophilia A. About 30% of cases of haemophilia B are the result of a spontaneous gene mutation.

Demographics/Location

Haemophiliacsa re primarily male although there are a rare instances of femleas having it too. The disease it self does have any numbers to any particular ethnicity but Haemophilia was featured prominently in European royalty and thus is sometimes known as “the royal disease”. Queen Victoria passed the mutation to her son Leopold and, through several of her daughters, to various royals across the continent, including the royal families of Spain, Germany, and Russia. In Russia, Tsarevich Alexei Nikolaevich, son of Nicholas II, was a descendant of Queen Victoria through his mother Empress Alexandra and suffered from haemophilia.

Statistics

Annual incidence of haemophilia is estimated at 1/5,000 male births and the prevalence is estimated at 1/12,000. About 400 babies are born with hemophilia each year. The exact number of people living with hemophilia in the United States is not knownbut the current estimate is about 20,000. In the United States, most people with hemophilia are diagnosed at a very young age.

What Symptoms are shown?

The major signs and symptoms of hemophilia are excessive bleeding and easy bruising. Bleeding can occur on externally or internally. Signs of excessive external bleeding include: bleeding in the mouth from a cut or bite or from cutting or losing a tooth, nosebleeds, heavy bleeding from a minor cut, bleeding from a cut that resumes after stopping for a short time. Signs of internal bleeding include blood in the urine (from bleeding in the kidneys or bladder) and blood in the stool (from bleeding in the intestines or stomach). Internal bleeding in the brain is a very serious complication of hemophilia that can happen after a simple bump on the head or a more serious injury. Many serious complications can also arise from bleeding into various body systems. Hemarthrosis is a bleeding into joint spaces and may be prevalent to those with a more serius from of the disease.

How is it Diagnosed?

Genetic testing and genetic counselling is recommended for families with haemophilia. Prenatal testing, such as amniocentesis, is available to pregnant women who may be carriers of the condition. Based on CDC data, the median age at diagnosis is 36 months for people with mild hemophilia, 8 months for those with moderate hemophilia, and 1 month for those with severe hemophilia. In about two thirds of cases, there is a family history of hemophilia. The diagnosis of hemophilia is made using a special blood test and most babies can be tested soon after birth. Sometimes prenatal genetic testing is done to diagnose hemophilia before birth.

Research

With the severe problems that arise with Haemophilia, numerous doctors are currently working to find a cure to treat this disease. One research study that may help to understand and find a cure dealt with Inhibitors in mild/moderate haemophilia A. Haemophilia A is caused by a deficiency of factor (F) VIII. Therapy is based on the replacement of FVIII to haemostatically adequate levels for the prevention or treatment of bleeds. Inhibitors neutralising the haemostatic effects of FVIII have been recognised as a complication of haemophilia since the introduction of replacement therapy. In MMHA, they occur later in life than in severe haemophilia and are generally associated with a change in bleeding pattern. Many of these patients experience severe spontaneous bleeding in joints and muscles Two cases were studied , patient 1 and patient 2. In the first , the patient was given drugs that prevented the formation of inhibitors and allowed the factor to prevail. In patient 2 , the patient received a different treatment and still getting that treatment ot prevent inhibitors from forming. In the second the patient did not get the same type of treatment and thus still suffered from bleeding. A range of therapeutic options to eradicate the inhibitor is currently available and a variety of treatments can also be used to treat the bleeding episodes. However, the optimal treatment regimen for the eradication of inhibitors in MMHA and for the treatment of bleeding episodes have yet to be established.

Social Impact

Many think people with hemophilia cannot live a normal life, which is not true. In order for people with hemophilia to live normal lives, they must take steps to prevent bleeding problems. The first step they do is to get in contact with the federal government about finding a hemophilia treatment center. This center will provide resources for families and people affected by hemophilia. Precautions one can take to avoid complications is to follow your treatment plan exactly, get regular checkups and vaccinations, and tell all of your health care providers that you have hemophilia, get regular dental care, and know the signs and symptoms of bleeding in joints and other parts of the body.

People who have mild hemophilia can take part in a variety of activities. Those who have severe hemophilia should avoid contact sports and other activities that are likely to lead to injuries that could cause bleeding. Physical therapists at Hemophilia Treatment Centers can develop exercise programs tailored to your needs and teach you how to exercise safely. It’s usually not safe for people who have bleeding problems to participate in contact sports, such as football, hockey, and wrestling and thus they should exercise extreme caution.. To prevent bleeding, one may be able to take clotting factors prior to exercise or a sporting event. Patients with hemophilia should avoid medicines that increase the risk of bleeding like aspirin, ibuprofen, naproxen, and other nonsteroidal anti-inflammatory medicines and should go to a doctort if there is bruising or tingling in their joints as this may cause them to bleed internally.