Sickle Cell Anaemia And Haemophilia: Sickle Cell Anaemia: It is an autosomal hereditary disease characterized by sickle-shaped (crescentic) red blood corpuscles under low oxygen content. It is caused by the substitution of valine for glutamine at the sixth position in the β chain of globin molecule of haemoglobin. The mutant haemoglobin molecule undergoes polymerization under low oxygen tension causing the change in the shape of the RBC from biconcave disc to an elongated sickle-like structure. The sickled red blood cells slowly creep in to and aggregate in the venous side of capillary systems. There the sickled erythrocytes are destroyed. This … Continue reading Sickle Cell Anaemia And Haemophilia