Question

Given below is the representation of amino acid composition of the relevant translated portion of b-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 (HbA peptide) indicates a normal human because glutamic acid in the sixth position is not substituted by valine.

B. The sufferer’s RBC become elongated and sickle shaped whereas the normal person will have biconcave RBCs.

C. Both males and females are likely to suffer from the disease equally because this is not a sex linked disease. It is an autosomal-linked recessive trait.