Number of mitochondrial DNA copies linked to MS progression

A recent study suggests that the number of mitochondrial DNA (mtDNA) copies in cells may decrease as multiple sclerosis (MS) progresses, indicating its potential as a biomarker for disease progression and treatment response.

Mitochondria, the energy-producing structures within cells, possess their own DNA. The quantity of mtDNA copies reflects mitochondrial health, and alterations in this number have been associated with various neurodegenerative diseases, including MS.

In this study, researchers employed a bidirectional two-sample Mendelian randomization approach to analyze genetic data from over 383,000 individuals of European ancestry in the UK Biobank, focusing on single-nucleotide polymorphisms (SNPs) linked to mtDNA copy number. They also examined genetic information from 12,584 MS patients registered with the International Multiple Sclerosis Genetics Consortium.

The analysis revealed no significant evidence that a lower mtDNA copy number causes MS progression. However, the reverse analysis indicated a causal relationship wherein MS progression leads to a reduction in mtDNA copy number. This finding suggests that as MS advances, it may impair mitochondrial function, resulting in fewer mtDNA copies.

These results highlight the potential of mtDNA copy number as a biomarker for monitoring MS progression and evaluating therapeutic responses. Nonetheless, further research is necessary to confirm its reliability and to understand the underlying molecular mechanisms, which could inform the development of targeted treatments.