Fig. 1

mQTL and AEI analysis of cartilage DNA and RNA from OA arthroplasty patients. A Schematic representation of the 16 CpGs analysed in this study across a 228 bp region. cg26736200 (CpG8) and cg26661922 (CpG13) are highlighted. B DNAm levels at the 16 CpGs stratified by rs34195470 genotype (GG, GA, AA). Methylation data is in the form of β-values ranging from 0 (no methylation) to 1 (complete methylation) and expressed as a percentage. In the violin plots, solid and dashed horizontal lines represent the median and interquartile range. Difference in numbers (n) due to variable number of patient samples per CpG passing quality control. P-values calculated by linear regression. * = P < 0.05; ** = P < 0.01; *** = P < 0.001; ns = not significant (P > 0.05). C Left, allelic (A/G) ratios in cartilage samples from nine OA patients heterozygous for WWP2 transcript SNP rs1052429 (A = OA risk allele). cDNA values are plotted as grey triangles, representing the mean of three replicates normalised to DNA values (represented by dotted line). Right, mean cDNA values for all samples represented as a box plot normalised to their corresponding DNA values, as above. Line inside the box represents the median, the box shows the interquartile range, the whiskers show the minimum and maximum values. P-value calculated by Wilcoxon matched-pairs signed rank test. * = P < 0.05