Sickle-cell anaemia is a genetic disorder caused by a point mutation in the gene encoding the beta-globin chain of haemoglobin. Which of the following represents the specific single base substitution at the sixth codon of the beta-globin mRNA that leads to this disease?

Step-by-step solution

Sickle-cell anaemia is caused by the substitution of Glutamic acid by Valine at the sixth position of the beta-globin chain of the haemoglobin molecule. This amino acid substitution is the result of a single base substitution at the sixth codon of the beta-globin gene. On the mRNA, the normal codon GAG (which codes for Glutamic acid) is replaced by the mutant codon GUG (which codes for Valine). The substitution of GUG to GAG represents the reverse of the actual mutation, while GAA GUA and UAA UAG are incorrect codo