Sickle cell anaemia is induced by - Sri Chaitanya Infinity Learn Best Online Courses for NCERT Solutions, CBSE, ICSE, JEE, NEET, Olympiad and Class 6 to 12

A
change of amino acid in $α$ -chain of haemoglobin
B
change of amino acid in $β$ -chain of haemoglobin
C
change of amino acid in both $α$ - and $β$ - chain of haemoglobin
D
change of amino acid in either $α$ - or $β$ -chain of haemoglobin

Solution:

Sickle cell anaemia is caused by the substitution of Glutamic acid (Glu) by Valine (Val) at the sixth position of the beta globin chain of the haemoglobin molecule. The substitution of amino acid in the globin protein results due to the single base substitution at the sixth codon of the beta globin gene from GAG to GUG. The mutant haemoglobin molecule undergoes polymerisation under low oxygen tension causing the change in the shape of the RBC from biconcave disc to elongated sickle-like structure.