Mitochondria are semi-autonomous organelles present in nearly every human cell that execute fundamental cellular processes including oxidative phosphorylation, calcium storage, and apoptotic signalling.
Mitochondrial dysfunction has been implicated as the underlying cause for many human disorders based on mechanistic in vitro and in vivo studies .
Complementary evidence comes from recent epidemiological studies that measure mitochondrial
- DNA Copy Number (mtDNA-CN),
- a marker of mitochondrial activity that can be conveniently
- measured from peripheral blood.
Since mitochondria contain their own unique set of genomes that are distinct from the nuclear genome, the ratio of mtDNA to nuclear DNA molecules (mtDNA-CN) in a sample serves as an accessible marker of mitochondrial quantity .
Indeed, observational studies suggest that individuals with lower mtDNA-CN are at higher risk of age-related complex diseases, such as coronary artery disease, sudden cardiac death, cardiomegaly, stroke, portal hypertension, and chronic kidney disease.