Critical review on The Haemophilias - Essay Example

mutations in the gene encoding blood coagulation factors VIII or IX respectively (Turgeon, 2004). The gene for factor VIII is situated near the tip of the long arm of X-chromosome (Xq 2.6 region). The gene for factor IX is close to that for factor VIII near the tip of long arm of the x-chromosome. Due to sex-linked pattern of inheritance, a carrier mother, carrying a gene for haemophilia on one of the two X chromosomes, transmits the gene for haemophilia to half of her female children and half of her male children.

Males who inherit the gene for haemophilia manifest the disease. On the other hand females who inherit the gene for haemophilia from their mothers would not show the defect and would act as the carrier, transmitting the defective gene to their offspring. The inheritance and clinical features of Haemophilia B are identical to that of haemophilia A (Turgeon, 2004). Both types of Haemophilias would show similar results for various blood tests, involving the normal bleeding time, clot retraction time, platelet count, Prothrombin time and increased APTT (Activated Partial Thromboplastin Time) (Hoffbrand et al, 2006). . The prevalence of Haemophilia A varies from 30-100 per million population (Hoffbrand et al, 2006).

While Haemophilia A is a relatively more common disorder, the incidence of Christmas disease is one fifth of that of haemophilia A. Depending on the levels of coagulation factors in the body, the disease can be classified into severe, moderate and mild. When the coagulation factor deficiency is less than one-two percent of normal, the clinical manifestations of haemophilia are severe, with the symptoms being frequent spontaneous bleeding into the joints, muscles and internal organs from early life itself.

Infants may suffer from profuse post-circumcision haemorrhage or develop recurrent joint and soft tissue bleeds and excessive bruising when they grow old and become active. Recurrent painful haemarthrosis and muscle haematomas may be predominant, resulting in joint deformity and crippling, especially if the disease is not adequately treated. Local pressure from haemophilic pseudo-tumours (encapsulated haematomas with progressive cystic swelling resulting from repeated haemorrhage) can cause entrapment neuropathy or ischaemic necrosis (Hoffbrand et al, 2006).

If the coagulation factor activity is between 2-10 % of the normal, the moderate manifestations of the disease are produced. Bleeding usually occurs after minor trauma, though occasionally spontaneous episodes of bleeding can occur too. Prolonged bleeding may occur after dental extractions. Spontaneous haematuria and gastro-intestinal haemorrhage, resulting from intramucosal bleeding can also occur (Hoffbrand et al, 2006). If the coagulation factor activity is greater than 10-30% of the normal,