Fig. 1
Characteristics of the differential DNA methylation positions (DMPs) associated with AS in the discovery cohort. A Flow diagram of the study design and analytical pipeline. B Volcano plot of Δβ vs. [-log10 (FDR)] of the filtered 740697 probes. Red dots and blue dots denote hypermethylated (n= 3294) and hypomethylated probes (n=1500) (FDR <0.05 and Δβ >0.05). C Principal component analysis (PCA) of DMPs show separation of AS cases form health controls (HCs). D DNA methylation heatmap showing DMPs between AS patients and HCs. E The distribution of hypermethylated and hypomethylated DMPs relative to CpG island regions. Shores are defined as the 2 kb away from CpG island and shelves as the 2 kb outside of a shore. Regions outside this 4 kb stretch are referred to as the “open sea.” F Genomic location of the hypermethylated and hypomethylated DMPs relative to promoters, 1st Exon, gene body, 3′UTR, and intergenic. G Representation of the top 20 Gene ontology (GO) biological process terms of DMPs. H Representation of the top 20 KEGG biological pathways associated with DMPs. Ratio represents the percentage of DMPs in each term or pathway. CIT, causal inference test; TF, transcription factor. FDR, false discovery rate