Quantification of DNA methylation at single-base resolution showed increased D-loop and decreased MT-ND1 gene methylation levels in the entorhinal cortex of AD patients with early-stage AD-related pathology compared to brain samples from control subjects, as well as a dynamic D-loop methylation pattern in the neocortex of APP/PSEN1 mice along with the progression of AD pathology [25]. This evidence concerns the gene PSEN1 and Alzheimer disease.