Table 2.
Methylation and expression levels of C9orf72
| Groups | P-Values | ||||||
|---|---|---|---|---|---|---|---|
| Variable | C9Plus | C9Minus | Control | Groupsa | C9Plus vs C9Minusb | C9Plus vs Controlb | C9Minus vs Controlb |
| Methylation, median (IQR), % | 4.05 (1.10–17.95) | 0.24 (0.15–0.33) | 0.46 (0.14–0.75) | 4.45e-15 | 1.70e-13 | 3.33e-07 | 0.17 |
| Total, median (IQR), % | 73.32 (65.96–86.20) | 110.70 (93.68–132.88) | 100.00 (87.48–111.27) | 2.06e-07 | 3.67e-07 | 9.08e-05 | 0.13 |
| Variant 1, median (IQR), % | 55.66 (48.14–72.82) | 80.10 (70.31–94.64) | 100.00 (74.87–110.67) | 1.07e-05 | 2.83e-04 | 3.65e-05 | 0.06 |
| Variant 2, median (IQR), % | 61.97 (55.23–73.67) | 104.75 (85.86–139.38) | 100.00 (90.04–120.12) | 9.66e-08 | 3.43e-07 | 1.10e-05 | 0.76 |
| Intron 1a, median (IQR), % | 411.20 (244.09–637.62) | 263.06 (103.15–398.10) | 100.00 (37.09–290.55) | 8.40e-04 | 0.01 | 4.03e-04 | 0.13 |
| Intron 1b, median (IQR), % | 61.18 (54.37–90.30) | 98.61 (75.58–109.73) | 100.00 (67.11–130.03) | 0.003 | 0.002 | 0.01 | 0.48 |
C9Plus patients with a C9orf72 repeat expansion, C9Minus patients without this expansion, Control control subjects without a neurodegenerative disease, IQR interquartile range
aA Kruskal-Wallis rank sum test is performed to determine whether a significant difference exists between groups for each of the six variables: levels of C9orf72 promoter methylation (Methylation), total C9orf72 transcripts (Total), variant 1 transcripts (Variant 1), variant 2 transcripts (Variant 2), intron 1a containing transcripts (Intron 1a), and intron 1b containing transcripts (Intron 1b; p < 0.008 is considered significant after Bonferroni correction)
bA Wilcoxon rank sum test is used when the Kruskal-Wallis test is significant for each of the three pairwise comparisons: C9Plus vs C9Minus, C9Plus vs Control, and C9Minus vs Control (p < 0.017 is considered significant after Bonferroni correction)