- Sickle cell anaemia is a human genetic disease that occurs in individuals homozygous for the autosomal recessive HbS allele. Sickle cell anaemia is fatal if left untreated. Which of the following statements is wrong?
A. The HbS allele, since in homozygosity, it causes a lethal pathological condition, has a low frequency in all human populations.
B. The HbS allele differs from the wild type allele by a point mutation affecting a single nucleotide.
C. The change of an amino acid resulting from the point mutation leads, in lack of oxygen, to hydrophobic interactions in the molecules of Y-globin
D. Heterozygous individuals in malaria prone populations have a major probability of survival.
E. The advantage of heterozygotes in malarial areas keeps relatively high (15 to 20 per cent) the frequency of the HbS allele
I understand why A is wrong - because the homozygosity can’t mean it has a low frequency in ALL human populations but could someone explain the reasoning behind the other options. Is the link to malaria something to do with the blood (mosquitos drink the blood??) I have no idea, but if someone could explain this to me and if we need to know these details for the exam.