Question

The ∆32 allele of CCR5 is found at the highest frequency in which of the following populations?

1) Japanese

2) South Americans

3) North Americans

4) Europeans

5) Africans

Answer 1

The Δ32 allele of CCR5 is most frequently found in European populations, providing resistance to HIV by preventing viral entry into T cells.

Step-by-step explanation:

The Δ32 allele of CCR5, associated with resistance to HIV infection, is found at the highest frequency in European populations. This particular genetic variation, known as CCR5-delta 32, causes a deletion mutation in the gene encoding the CCR5 protein, which is a coreceptor on the surface of T cells. The mutation leads to a receptor that HIV cannot effectively bind to, therefore blocking viral entry and reducing susceptibility to HIV infection. It has been suggested that this mutation may have been advantageous in European populations during historical epidemics such as the plague or smallpox, but its exact origins and selective pressures remain a matter of debate.