Detection of Allergy-Related TPSAB1 Copy Number Variation by MALDI-TOF Nucleic Acid Mass Spectrometry

Allergic diseases have been linked to genetic variations in TPSAB1 and TPSB2. This study aimed to develop a Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) method for simultaneous copy number detection of TPSAB1 and TPSB2.

We established a multiplex PCR-tandem MALDI-TOF MS assay for TPSAB1 and TPSB2 copy number analysis. To validate the method, 35 standard samples pre-validated by droplet digital PCR (ddPCR) were used to assess accuracy, sensitivity, repeatability, and stability. Additionally, we applied the method to 274 randomly selected population samples for clinical evaluation.

The developed MALDI-TOF MS assay demonstrated high reliability, achieving 100% accuracy in standard samples. The detection limit for the standard template was 20 ng, with repeatability (CV: 8.41 - 13.60%) and stability (CV: 7.75 - 17.38%) within acceptable ranges. In the population cohort, the carrier rate for TPSAB1 copy number gain (> 2 copies) was 12.41%.

The MALDI-TOF MS-based method is a robust, cost-effective, and high-throughput molecular diagnostic tool, particularly suited for differentiating highly homologous TPS genes. Its high accuracy and reliability make it a promising clinical assay for TPSAB1 and TPSB2 copy number analysis.