Two pathogenic point mutations exist in the authentic mitochondrial genome, not in the nuclear pseudogene

Technical advancements in molecular genetics have shown various mitochondri al DNA (mtDNA) abnormalities in patients with mitochondrial myopathies. Rec ently, it has been revealed that, in these patients, the nuclear DNA carrie s sequences similar to those of the mtDNA (nuclear pseudogene) and it has s everal point mutations previously reported to be pathogenic. We verified th e existence of the T3250C and T3291C mutations, which we have found in pati ents with mitochondrial myopathy, in the authentic mitochondrial genome, A long polymerase chain reaction provides a powerful tool for avoiding nuclea r pseudogene amplification and for ruling out ambiguity in the detection of the mutation for diagnosis.