Sickle cell anaemia: Sickle-cell anaemia is an autosome-linked recessive trait exhibiting a change in the shape of the red blood cells from biconcave disk to sickle shape under low oxygen tension. It is a result of the replacement of GAG by GUG leading to the substitution of Glu by Val at the sixth position of beta-globin chain of haemoglobin. It is characterised by low haemoglobin count and other symptoms of anaemia such as fatigue and irritability, swelling on hands and legs, pain in joints, constant low-grade fever, etc. There is no particular treatment for sickle cell anemia, the treatments which are available provide symptomatic relief from the symptoms associated with this disorder.