Quantitative assessment of mitochondrial DNA copy number is an emerging field of study in the diagnosis and evaluation of age-related pathology and frailty in the elderly, along with the assessment of other acute and chronic diseases that are often necessary within this patient cohort.

Aim: to analyze current advances in the quantitative assessment of mitochondrial DNA copy number as a tool for diagnosing and evaluating age-related pathology, frailty, and comorbid conditions in the elderly.

Material and methods. The author independently conducted a thorough review of literature available from the NIH, PubMed database, providing a detailed narrative of updates in the field. As clinical trials seek to further develop practical techniques, the author then undertook a search of relevant trials at ClinicalTrials.gov, including this as a table in the body text.

Results. The review provides a thorough examination of the theoretical foundation of mitochondrial biogenesis, fusion-fission processes, and control and repair of mitochondrial genetic material, and how advances in these topics may be applied to better understand the processes being measured in quantitative mitochondrial DNA analysis.

Conclusions. Detailed examination of the crosstalk between mitochondrial control proteins and nuclear factors, and the fundamental role of energy homeostasis apparatus within ageing processes underpins the advances in translational aspects of mitochondrial medicine and allows more effective exploitation of this emerging field.