Methylation analysis of DNA in Alzheimer's disease

DNA methylation represents a physiological mechanism required for neuronal differentiation, brain development, and memory formation, and could be impaired by environmental insults that, if occurring in early life, can lead to lasting epigenetic modifications likely contributing to neurobehavioral and neurodegenerative disorders later in life. Changes in DNA methylation patterns could also result from the presence of gene mutations, from the accumulation of neurotoxic molecules, or during the progression of a degenerative process that takes place in the brain, making it difficult to distinguish between changes occurred before the onset of dementia and those resulting as a consequence of the disease. Many investigators observed global and gene-specific methylation changes in postmortem brain regions and in peripheral blood DNA from Alzheimer's disease patients, and recent genome-wide approaches are increasing the number of potential methylation biomarkers of the disease. Additional studies and meta-analyses of available data are, however, required to confirm these findings and to address the clinical utility of those biomarkers