Methylation mValues

M-values of frontal methylation data from the RiMod-FTD resource (https://www.biorxiv.org/content/10.1101/2020.12.01.405894v4). <br> Data was processed as follows: <br> The Infinium MethylationEPIC BeadChip, which consists of 866,091 CpG locations, data was analyzed using the minfi R package. We removed all sites with a detection P-value above 0.01, on sex chromosomes and with single nucleotide polymorphisms (SNPs), leaving 810,290 loci for analysis. Data normalization was done using stratified quantile normalization. Sites with a standard deviation below 0.1 were considered uninformative and filtered out, leaving 170,595 sites that were used to perform a principal component analysis.