Hemophilia (Blood Clotting Disorder)

Blood is one of the important fluids that circulates through various body compartments, distributing oxygen and nutrition and removing waste. It travels through blood vessels (arteries and veins) across the entire body, called blood vessels. Ruptured vessels cause blood to leak out and clots form to seal up the tear where possible. This protective mechanism is known as blood clotting or coagulation. Blood clotting is an inherent property, in which liquid blood coagulates into solid and prevents excessive blood loss in cases of injury. This is achieved by inactivated chemicals circulating the blood known as clotting factors.

Definition

Hemophilia commonly refers to a group of bleeding diseases, in which the clotting ability of the blood is lost. Most common forms of hemophilia are inherited but they can also be acquired.  The condition usually starts from birth and lasts for a lifetime when inherited. Hemophilia is a consequence of a lack of one or more clotting factors and associated substances. The danger lies in uncontrolled bleeding even from small cuts and wounds. Without proper medical attention, a person with hemophilia (hemophilic) can bleed to death.

Children of Hemophilics

Hemophilia is a range of X-linked recessive disorders, which usually affects males and is carried in the family by females. It is called the “royal disease” as Queen Victoria was a hemophilia carrier, who passed her genes to several royal families through her son and granddaughters. A woman having hemophilia gene, who has normal husband, will transmit the disease to fifty percent of their children, either girl or boy. A hemophiliac man having a normal wife will have all diseased daughters but normal sons. Therefore, hemophilia is inherited in a criss-cross manner, where a woman transmits her genes to granddaughters through her son.

Causes

Lack of clotting factors VIII and IX prevents blood coagulation, causing incessant bleeding. Fault with one or more genes that produce fewer amounts of clotting proteins, constitute the major reason behind hemophilia. Based on the prevalence and clotting factors involved, hemophilia is mainly classified into two main types – hemophilia A and B.

Types

  • Hemophilia A occurs due to the absence or scarcity of clotting factor VIII. The majority of hemophilics suffer from this class of hemophilia.
  • Hemophilia B occurs because of a reduced quantity or lack of clotting factor IX.

Depending on the available amounts of clotting protein, the conditions could vary from severe to mild.

  • Hemophilia C occurs due to the lack of clotting factor XI. Symptoms range from moderate to mild. It is not X-linked and therefore cannot be transmitted to next generation through either parent.

In some rare exceptional cases, patients with less than optimum amounts of factor X also precipitate similar diseased conditions. Some hemophilia patients have defective gene coding for enzyme, thrombin that catalyzes the formation of clotting protein, fibrin, from its precursor fibrinogen. Although most forms of hemophilia are inherited, in acquired forms, body starts producing destructive proteins (antibodies) against clotting factors that prevents normal blood clotting.

Symptoms

Symptoms of hemophilia usually become evident when there is some injury like a cut or wound.  In healthy person, blood usually takes 1 to 4 minutes to clot. This ability is challenged in case of hemophilia, where even minor cuts and wounds leads to prolonged bleeding. Incessant flow causes heavy blood loss and evokes the onset of secondary complications like weakness, difficult breathing and even death. Based on the severity of the disease, the symptoms often presented are :

Mild Hemophilia

  • No early symptoms unless injured or wounded
  • Prolonged bleeding from minor cuts and wound

Moderate Hemophilia

  • Symptoms start showing in early childhood
  • Easily bruised with a simple fall or blow
  • Internal bleeding of joints with severe pain (hemarthrosis)

Severe Hemophilia

  • Symptoms are seen very early, with increased frequency and severity
  • Spontaneous bleeding for no apparent reason from nose and gums
  • Spontaneous appearance of large bruises
  • Blood loss through urine and stool
  • Internal bleeding from joints with severe pain and swelling

Severe hemohiliacs also suffer from brain hemorrhages because of internal bleeding in the brain. Usually, brain hemorrhages are not spontaneous but accidents or a heavy blow to the head may precipitate such conditions.

Diagnosis

Hemophilia is a life-long ailment, which could be controlled with proper care and treatment. Early diagnosis is key to managing the condition before complications arise. Common tests for diagnosis are:

  • Blood test – to analyze the clotting time and to assess the available amounts of clotting proteins in the blood.
  • Chorionic Villi Sampling (CVS) – suitable for detection of hemophilia before birth. In pregnant women, sample from the outermost fetal layer (chorion) could be used for genetic analysis of the unborn child.

Based on the understanding of the inheritance of hemophilia gene, a family tree (phylogenetic tree) depicting the transfer of hemophilia gene across several generations, could be made. It helps in predicting the diseased and carriers in a family with a history of hemophilia and also helps in avoiding matches (marriages) that could possibly bore diseased children.

Treatment

Available treatment options for hemophilia are widely available but not always affordable for every hemophilic.

Replacement Therapy

This is the most common treatment strategy, where the deficient clotting factors are replenished artificially through blood or plasma concentrate infusions. Although it provides immediate relief in even emergency cases, its frequent usage is challenged by secondary viral infections like HIV. Along with the replacement therapy, certain anti-fibrinolytics are also prescribed that help prevent breakage of clot.

Hormone therapy

An artificially synthesized hormone, desmopressin, is used to combat moderate to mild symptoms by releasing the stored clotting factors and retaining them for longer time in the blood.

Recombinant Factor Therapy

This recently proposed treatment uses artificially synthesized recombinant clotting proteins could be injected directly into the blood. The possibility of contracting viral infections is also minimized with recombinant proteins.

 

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