Question

Sickle cell anaemia is caused by substitution of sixth position

• A. Valine by glutamic acid in $\alpha$-chain of Hb
• B. Valine by glutamic acid in $\beta$-chain of Hb
• C. Glutamic acid by valine in $\alpha$-chain of Hb
• D. Glutamic acid by valine in $\beta$-chain of Hb
• E. Glutamic acid by methionine in $\alpha$-chain of Hb.

Answer 1

The correct option is D Glutamic acid by valine in $\beta$-chain of Hb

Sickle cell anaemia is an autosomal disorder. It is the most common genetical disorder appear in Africans. The disease is due to the substitution of sixth codon in gene coding for the b-chain of Haemoglobin. Due to this, sixth amino acid in b-chain of Haemoglobin Glutamic acid is replaced by valine. The main symptom of this disorder is decrease of oxygen uptake.

So, the correct option is ‘Glutamic acid by valine in b-chain of Haemoglobin’.