Answer:
The correct answer to the question: The mutation in the receptor is in:____, would be: NPXY motif.
Explanation:
In the case of this infant, who is unable to acquire antibodies from his mother´s breast milk, even though his body successfully produces the necessary receptors that would normally allow these antibodies to be bound and internalized in the cells, the reason why this happens is that, even though the receptors are there, they have a mutation in their correct sequence, which prevents the correct binding and internalization of the antibodies by the cells because although the antibodies are seen on the plasma membrane, they are not inside the coated pits that would be necessary for that internalization. This mutation is known as the NPXY motif. The NPXY motif is a sequence that is often found on the cytoplasmic end of LDL (low density lipoprotein) receptors.
