Table 4. Quantification of MLH1 promoter methylation by pyrosequencing.
| MLH1 promoter C region | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| CpG position | |||||||||||
| Family | Individual | Sample | −15 | −14 | −13 | −12 | −11 | Mean | SD | Min | Max |
| A | II.1 (case 1) | PBL | 32.0 | 38.1 | 36.1 | 31.7 | 33.6 | 34.3 | 2.8 | 31.7 | 38.1 |
| sperm | 2.1 | 0.0 | 3.8 | 2.1 | 1.4 | 1.9 | 1.4 | 0.0 | 3.8 | ||
| B | case 34 | PBL | 22.1 | 21.6 | 20.1 | 17.1 | 17.7 | 19.7 | 2.3 | 17.1 | 22.1 |
| RKO | 95.5 | 96.5 | 94.2 | 92.6 | 95.9 | 94.9 | 1.6 | 92.6 | 96.5 | ||
| CEPH | 2.2 | 2.15 | 3.6 | 2.55 | 2.3 | 2.6 | 0.6 | 2.2 | 3.6 | ||
| MLH1 promoter D region | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CpG position | ||||||||||||||
| Family | Individual | Sample | −6 | −5 | −4 | −3 | −2 | −1 | 1 | 2 | Mean | SD | Min | Max |
| A | II.1 (case 1) | PBL | 39.0 | 50.0 | 38.9 | 36.4 | 43.8 | 33.3 | 32.1 | 39.4 | 39.1 | 5.8 | 32.1 | 50.0 |
| sperm | 0.0 | 5.3 | 0.0 | 1.6 | 6.5 | 2.9 | 0.0 | 1.7 | 2.3 | 2.5 | 0.0 | 6.5 | ||
| B | case 34 | PBL | 19.7 | 20.5 | 19.1 | 19.2 | 17.2 | 18.3 | 19.8 | 19.2 | 19.1 | 1.0 | 17.2 | 20.6 |
| RKO | 95.5 | 92.6 | 84.0 | 90.2 | 76.1 | 72.7 | 81.0 | 93.7 | 85.7 | 8.6 | 72.7 | 95.5 | ||
| CEPH | 3.4 | 5.7 | 0.0 | 0.0 | 9.4 | 3.8 | 2.7 | 2.9 | 3.5 | 3.0 | 0.0 | 9.4 | ||
Each sample was run in triplicates. Methylation at each specific CpG was calculated as the mean of the triplicates. Values for each specific CpG within the region are given in percentage. Average percentage of methylation of the whole region was calculated as the mean for the five CpGs analyzed in C region and the eight CpGs in the D region. Both peripheral blood lymphocytes (PBL) and sperm from the proband (II.1) were analyzed. DNA from the colorectal cancer cell line RKO was used as positive control. CEPH DNA was used as negative control. Each CpG analyzed is numbered according to its position relative to the translation initiation codon.