Which of the following best describes the impact of point mutations on short probes?

Point mutations refer to changes in a single nucleotide within a DNA or RNA sequence. When considering short probes, which are typically designed to bind to specific target sequences for purposes like detection in molecular diagnostics, the implication of point mutations is significant.

Point mutations can lead to mismatches between the probe and the target sequence. This mismatch can hinder the ability of the probe to successfully bind to the target, thereby reducing the effectiveness of the detection process — a condition known as decreased sensitivity. In molecular diagnostics, sensitivity is key because it reflects the assay's ability to accurately identify the presence of a target nucleic acid at low concentrations.

When point mutations are present, the fidelity of the probe's binding is compromised, which can lead to false negatives, where a target that is genuinely present may go undetected because the probe fails to hybridize correctly. Thus, the presence of point mutations affects the reliability of the probe and subsequently diminishes the sensitivity of the assay, making it difficult to accurately detect specific sequences of interest. Therefore, diminished sensitivity is the most accurate description of the impact of point mutations on short probes.