You are studying an individual with very low levels of insulin in her blood. Further analysis indicates that cells of her pancreas are producing normal levels of this protein, but it is accumulating in the cytoplasm rather than being secreted from the cells. Which hypothesis makes the most sense to explain this observation?

a small deletion occurs in the nucleotide sequence at the aminoterminal of the gene in the signal sequence

Explanation:

A deletion in the sequence of nucleotide that code for the small signal sequence responsible will affect the release of insulin outside the cells because the signal sequence is responsible for carrying the insulin outside the cells. The cells of pancreas are producing the insulin normally but due to mutation in the signal sequence it can not release out of the cells and accumulate inside the cells.