Question

Given below is the representation of amino acid composition of the relevant translated portion of `beta`-chain of haemoglobin, related to the shape of human red blood cells.

(a) Is this representation indicating a normal human or a sufferer from certain related genetic disease? Give reason in support of your answer.
(b) What difference would be noticed in the phenotype of the normal and the sufferer related to this gene?
(c) Who are likely to suffer more from the defect related to the gene represented the males, the females or both males and females equally? And why?

Answer 1

(a) This representation indicates a normal human because in the respective amino acid chain, Glutamic and is present at the 6th position.
(b) In the sufferer who exhibits sickle cell trait, defect is caused by the substitution of Glutamic acid (Glu) by valine (Val) at the 6th position of Beta globin chain of the haemoglobin.
(c) Both the males and females suffer equally because sickle cell anaemia is not a sex linked disease. It is an autosomal disease and sickle shaped RBC will cause equal deficiency of oxygen in both males and females.