Colorimetric LAMP assay for detection of the TP53 R337H single- nucleotide variant

The human TP53 gene plays a central role in maintaining genomic stability, and germline variants in this gene are associated with hereditary cancer predisposition syndromes. The R337H single-nucleotide variant (SNV), highly prevalent in the Brazilian population, is an important genetic marker for cancer risk assessment and clinical surveillance. However, detection of SNVs usually requires sequencing or real-time PCR–based methods, which may not be readily available in resource-limited settings. In this study, we developed a colorimetric loop-mediated isothermal amplification (LAMP) assay for detection of the TP53 R337H variant using a competitive primer design that enables single-nucleotide discrimination without probes or fluorescence instrumentation. The assay was evaluated using a panel of clinical DNA samples previously characterized by sequencing. The method achieved a sensitivity of 100.00% (83.16%–100.00%), specificity of 95.00% (75.13%–99.87%), and overall accuracy of 97.50% (86.84%–99.94%). The limit of detection (6 ng µL ^− 1 of DNA) was compatible with DNA concentrations typically obtained from whole-blood extraction. These results indicate that colorimetric SNV-LAMP provides a simple and low-cost approach for detection of the TP53 R337H variant. Further validation in larger cohorts and field settings is required before large-scale implementation.