I've been using methylumi to extract beta-vals, m-vals, etc. from my 24 idat files and find many instances of beta values = "NA" even though the detection p values are far less than 0.05. What causes a beta value of "NA"? K_samps <- read.table("KyleA_met27k_Samples_051812.txt",row.names=2,sep='\t',head er=T) K_idat<-methylumIDAT(barcodes = K_samps$barcode, pdat = K_samps) K_bgcorr <- methylumi.bgcorr(K_idat) K_betaVals <-betas(K_bgcorr )