QS Study

Haemophilia is a sex-linked inherited disease transmitted by females to males who manifests the signs of disease but female themselves show no symptoms. It is an inherited bleeding disorder where the blood doesn’t clot properly. It is caused when blood does not have enough clotting factor. A clotting factor is a protein in blood that controls bleeding.


(A) Haemophilia – A (Classical haemophilia / true haemophilia):

Cause: Factor- ‘VIII’ deficiency (85%)

(B) Haemophilia – B (Christmas disease)

Cause: Factor ‘IX’ delicacy (15%)

Clinical features-

  • Anaemia,
  • Bleeding into the tissues, joint spaces producing haematoma.
  • Fever
  • Wound bleeding.

Fig: disease transmitted by parents

Symptoms of this include: a severe headache, stiff neck, vomiting, slurred speech, double vision, paralysis etc.

Laboratory findings

(A) Coagulation time – Prolonged

(B) Bleeding time – Normal

(C) Prothrombin time – Normal

(D) Platelet count – Normal

(E) Partial thromboplastin time – Prolonged.

Haemophila may occur in heterozygous female due to unfavorable lyonization that is inactivation of normal X chromosome in most of the cells of the body.

Clinical classification: There are 3 levels of severity in haemophilia: mild, moderate and severe. The level of severity depends on the amount of clotting factor in the person’s blood. It depends on the level of factor VIII activity-

Fig: Clinical classification