Mitochondrial DNA mutation detection by electrospray mass spectrometry.
BACKGROUND: Mitochondrial DNA (mtDNA) mutations cause a large spectrum of clinically important neurodegenerative, neuromuscular, cardiovascular, and endocrine disorders. We describe the novel application of electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) to the rapid and accurate identification of pathogenic mtDNA variants. METHODS: In a blinded study, we used ESI-FTICR MS to analyze 24 unrelated samples of total cellular DNA containing 12 mtDNA variants and compared the results with those obtained by conventional PCR-restriction fragment length polymorphism (PCR-RFLP) analysis and gel electrophoresis. RESULTS: From the 24-sample blinded panel, we correctly identified 12 of the samples as bearing an mtDNA variant and found the remaining 12 samples to have no pathogenic variants. The correlation coefficient between the 2 methods for mtDNA variant detection was 1.0; there were no false positives or false negatives in this sample set. In addition, the ESI-FTICR method identified 4 single-nucleotide polymorphisms (SNP) that had previously been missed by standard PCR-RFLP analysis. CONCLUSIONS: ESI-FTICR MS is a rapid, sensitive, and accurate method for the identification and quantification of mtDNA mutations and SNPs.