Table 2. Distribution of aberrant methylation of DBC1 and CDKN2B promoters in two independent AML series.
| DBC1* | CDKN2B* | |||||||||||
| Original Set Illumina Array | Validation Set MSP Analysis | Original Set Illumina Array | Validation Set MSP Analysis | |||||||||
| N | Methylated | N | Methylated | N | Methylated | N | Methylated | |||||
| Favorable Group | ||||||||||||
| t(15;17) | 9 | 9 | (100%) | 19 | 16 | (84%) | 9 | 5 | (55.5%) | 7 | 3 | (42%) |
| inv(16) | 11 | 9 | (82%) | 9 | 5 | (56%) | 11 | 4 | (36.4%) | 0 | - | |
| t(8;21) | 10 | 10 | (100%) | 12 | 8 | (66%) | 10 | 7 | (70%) | 3 | 2 | (66%) |
| Intermediate Group | ||||||||||||
| Normal Karyotype | 41 | 21 | (51.2%) | 111 | 54 | (49%) | 41 | 15 | (36.6%) | 99 | 42 | (42%) |
| Trisomy 8 | 7 | 6 | (86%) | 12 | 6 | (50%) | 7 | 2 | (28.6%) | 3 | 1 | (33%) |
| Other Intermediate | 13 | 9 | (69%) | 21 | 12 | (52%) | 13 | 4 | (31%) | 10 | 3 | (30%) |
| Adverse Group | ||||||||||||
| Complex Karyotype | 14 | 1 | (7%)** | 16 | 11 | (69%) | 14 | 3 | (21.4%) | 7 | 2 | (29%) |
| MLL | 7 | 7 | (100%)*** | 2 | 0 | (0%) | 7 | 1 | (14%) | 2 | 1 | (50%) |
| Other Adverse | 4 | 1 | (25%) | 7 | 1 | (14%) | 4 | 1 | (25%) | 2 | 1 | (50%) |
| Other | - | - | 35 | 15 | (42%) | - | - | 18 | 6 | (33%) | ||
| Total | 116 | 71 | (61%) | 244 | 128 | (52%) | 116 | 43 | (37%) | 151 | 61 | (40%) |
MLL, mixed lineage leukemia; MSP, methylation-specific polymerase chain reaction; N, number of cases. (*)The frequencies of methylated DBC1 and CDKN2B in both sets of samples were compared in all categories using the Fisher exact test. There were no statistical differences in the frequencies, except for (**) p = 0.001 and (***) p = 0.28.
Other: Cases with no available cytogenetic data.