Rapid identification of unknown heteroplasmic mitochondrial DNA mutations with mismatch-specific surveyor nuclease

Identification of mitochondrial DNA (mtDNA) mutations is essential for diagnosis and genetic counseling of mitochondrial diseases. In this chapter, we describe a strategy for the rapid identification of heteroplasmic mtDNA mutations that can be used routinely in molecular genetic laboratories. This protocol involves the following three steps: (i) PCR amplification of the entire human mitochondrial genome with 17 overlapping PCR products, (ii) localization of mtDNA mismatch(es) after digestion of the 17 amplicons by Surveyor Nuclease, a member of a family of plant DNA endonucleases that cleave double-strand DNA at any mismatch site, and (iii) identification of the mutation by sequencing the region containing the mismatch.