Recent advances in CRISPR-based single-nucleotide fidelity diagnostics.

Accurate point-of-care (PoC) detection of single nucleotide variants (SNVs) can support rapid and cost-effective clinical decision-making in tasks such as diagnosing pathogenic genetic variants, identifying pathogen resistance, or tracing viral lineage differentiation. Traditional nucleic acid diagnostics involving PCR and sequencing lack PoC applicability. CRISPR-based diagnostics (CRISPRdx) offer the necessary operational simplicity and ability to integrate specific nucleic acid sequence detection with isothermal amplification. However, achieving single-nucleotide fidelity is not self-evident and often requires empirical optimization. This Review explores recent strategics aimed at refining CRISPRdx specificity for SNV detection including various ways of tactical guide RNA (gRNA) design, fine-tuned effector selection, and improved reaction conditions. While the approaches described here are functional and can be occasionally combined, they often require optimizations to support specific clinical aims. Looking ahead, leveraging computational and AI tools for gRNA design, and harnessing newly discovered CRISPR systems, will broaden applicability and improve precision detection of CRISPRdx in diverse clinical settings.