Final answer:
The deletion of 2 consecutive nucleotides in a DNA sequence causes a frameshift mutation, altering the reading frame, and thus potentially affecting the whole amino acid sequence of the expressed protein.
Step-by-step explanation:
The deletion of 2 consecutive nucleotides in a DNA sequence would result in a frameshift mutation. A frameshift mutation is a type of mutation where the deletion or insertion of one or more nucleotides that is not divisible by three causes a change in the reading frame of the genetic code. This usually has a significant impact on the resulting protein because the entire amino acid sequence after the mutation can be altered.
Frameshift mutations can lead to the creation of a premature stop codon or can extend the length of the polypeptide by pushing a stop codon further down the sequence. With a deletion or an insertion, the triplet nature of codon reading is disrupted, and since each triplet code specifies an amino acid, the proteins synthesized from such mutated DNA will differ from the original by more than just a single amino acid change.