Fig. 2
mQTL analysis of cartilage DNA from foetal samples. A DNAm levels at the 16 CpGs stratified by rs34195470 genotype. 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 analysis. * = P < 0.05; ** = P < 0.01; ns = not significant (P > 0.05). B Plot of the mean cartilage DNAm values for each CpG for the OA arthroplasty patients (grey) and for the foetal samples (orange). C Comparison of the mean DNAm values for each CpG between the OA arthroplasty patients and the foetal samples. r2 value determined by linear regression. Line of best fit and 95% confidence intervals shown. D Heatmap showing the influence of the rs34195470 genotype on DNAm levels at the 16 CpGs in the foetal samples and in the OA arthroplasty patients. r2 values determined by linear regression and expressed as a percentage