Question

Sickle cell anaemia is due to transversion mutation in which:

• A. Instead of glutamic acid, valine comes at number 6^th position in one of $\beta$ chain of Hb
• B. Instead of valine, glutamic acid is inserted at number 6^th position of $\beta$ - chain of Hb
• C. Valine is inserted at number 6^th position in $\alpha$ chain of Hb
• D. Glutamic acid is substituted by valine at number 6^th position of $\alpha$ - chain of Hb

Answer 1

Answer: (A)

Sickle cell anemia is a recessive autosomal gene disorder that follows Mendelian inheritance pattern. Sickle cell anemia is a type of genetic blood disorder which is inherited from the parents. The person suffering from it develops an abnormal haemoglobin that leads to elongated and curved or sickle shaped RBC. Such condition occurs when the individual inherits two abnormal copies of gene for beta globin chain of haemoglobin from each parent. Normally, the red pigment molecule is made of four polypeptide chains two α-chains and two $\beta$ -chains. Sickle cell anaemia results in glutamic acid (Glu) is replaced by valine (Val) at sixth position in each of two $\beta$ globin chain of haemoglobin. Such mutation is called as substitution mutation.