Cas14a1-Mediated Nucleic Acid Diagnostics for Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is the main genetic cause of infant death. In >95% of the patients with SMA, the disease is caused by a single hotspot pathogenic mutation: homozygous deletion of exon 7 of the survival motor neuron 1 gene (SMN1). Recently, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein (Cas)-based assays have been developed as a promising new option for nucleic acid detection. Here, we developed a Cas14a1-based assay combined with asymmetric PCR to establish a method for detection of the homozygous deletion of SMN1 exon 7 in SMA patients. The minimum detectable concentration of genomic DNA reached 5.26 aM with our method, and the assessment of its detection performance in 33 clinical samples revealed that the results were completely consistent with those of multiple ligation-dependent probe amplification and quantitative PCR. Thus, our novel nucleic acid diagnostics combining CRISPR/Cas14a1 and asymmetric PCR not only provides specific and sensitive testing of the deletion of SMN1 exon 7, but also holds promise for an accurate detection platform of genetic diseases and pathogens in multiple sample types.