The fact that higher methylation of frataxin can extend life, as indirectly suggested by its epigenetic age lowering effect is somewhat counterintuitive: defects in the expression of this mitochondrial protein cause the neurodegenerative syndrome of Friedreich's ataxia [37, 38], which is also accompanied by cardiomyopathy, diabetes mellitus, and reduced life expectancy [39]. This evidence concerns the gene FXN and diabetes mellitus.