Fig. 2

Bisulfite sequencing of the MLH1 shore in normal colorectal tissue and matched colorectal tumours. a The MLH1 upstream region is indicated, including rs1800734 coordinates. The position of each CpG interrogated by bisulfite sequencing relative to the MLH1 translation start site is designated by a circle. Each CpG is numbered 1 to 6 in a 5ʹ to 3ʹ direction. The grey circles represent CpG sites also interrogated within the MethyLight amplicon. b Methylation patterns in six normal colorectal tissue samples and matched tumours at the MLH1 shore, with rs1800734 genotype indicated. Empty circles represent unmethylated CpGs and filled circles represent methylated CpGs. c Graphical representation of bisulfite sequencing results. For each sample at each CpG site, the percent of methylated CpGs was calculated. The mean percent of methylated CpGs was then calculated for each genotype and tissue source grouping: GG normal, GA normal, AA normal, GG tumour, GA tumour, and AA tumour. Pearson’s chi-square test was used to compare the total number of methylated CpGs at each CpG site. Error bars represent standard deviation. **P < 0.01; ***P < 0.001