In sickle cell anaemia, the sequence of amino acid from first to seventh position of `beta`-chain of haemoglobin S (HbS) is

Options

A. His, Leu, Thr, Pro, Glu, Val, Val
B. Val, His, Leu, Thr, Pro, Glu,Glu
C. Thr, His, Pro, Val, Pro, Val, Glu
D. Glu, His, Leu, Pro, Val, Glu, Glu

Answer

C

Explanation

In sickle-cell anaemia, the correct seqence of amino acid from 1-7th position of the B-chain haemoglobins is Val - His - Leu - Thr - Pro - Val - Glu
1 2 3 4 5 6 7
It occurs when amino acid glutamine (Glu)at position 6 is replaced by amino acid valine (Val)